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THE  MECHANIC'S  FRIEND, 


PRINTED  BY  BALLANTYNE  AND  COMPANY 
EDINBURGH  AND  LONDON 


THE 


MECHANIC'S  FRimC; 


w 


A   COLLECTION    OF 

RECEIPTS  AND  PRACTICAL  SUGGESTIONS 

RELATING  TO 

^^:;                .: 

AQUARIA,       ' 

GL  UES, 

PYROTEC'HNy,      ''^ 

BRONZING, 

HOROLOGY, 

SOLDERS, 

CEMENTS, 

LACQUERS, 

DRA  WING, 

LOCOMOTIVES, 

STEAM-ENGINE, 

DYES, 

MAGNETISM, 

TELEGRAPHY, 

ELECTRICITY, 

ME  TA  L-  WORKING, 

TAXIDERMY, 

GILDING, 

MODELLING, 

VARNISHES, 

GL  A  SS-  IVOR  KING, 

PHOTOGRAPHY, 

WA  TERPROOFING, 

MISCELLANEOUS  TOOLS,  INSTRUMENTS,  MACHINES,  AND  PROCESSES 
,     CONNECTED  WITH  THE  CHEMICAL  AND  MECHANICAL  ARTS. 


fflSSitfj  l^ttmerous  JBtagrams  anti  SJaootrcuts. 


EDITED  BY 

WILLIAM  E.  A,  AXON,  M.R.S.L.,  F.S.S. 

MEMBER  OF  THE  LITERARY  AND  PHILOSOPHICAL  SOCIETY  OF  MANCHESTER,   ETC.   F.TC. 

BOSTOH^CfOBtEGE  LIBRAK) 

NEW   YORK:      - 

D.     VAN     NO  STRAND; 

1875. 
BOSTON  COT.LTO1 

CBEgT^UT  BILL,  MA^S. 


PREFACE. 


The  present  differs  in  some  important  particulars 
from  the  many  "  receipt-books  "  which  have  preceded 
it.  It  is  the  result,  not  so  much  of  individual  judg- 
ment as  of  the  action  of  a  number  of  "  friends  in 
council,"  whose  varied  practical  experiences  have 
inspired  the  instructions  and  hints  it  contains. 
The  articles  of  which  the  volume  consists  have 
already  appeared  in  the  English  Mechanic,  a  well- 
known  periodical,  in  whose  pages  lovers  of  science, 
practical  mechanics,  chemists,  photographers,  &c.  &c., 
have  for  years  past  been  in  the  habit  of  affording 
mutual  help  to  each  other.  Hence  almost  every  item 
of  information  in  the  present  volume  is  a  statement 
of  a  difficulty  experienced  by  one  person,  and  re- 
sponded to  by  another,  who  has  already  met  and 
overcome  it.  This  fact  will  stamp  the  book  with  a 
practical  value  in  the  eyes  of  those  who  know  how 
much  more  important  such  individual  experience  is 
than   any  mere  theory  or  tradition.     The  workman 


PREFACE. 


who  looks  here  for  help  will  know  that  he  is  listening 
to  those  who  have  been  in  his  own  circumstances, 
and  who  by  perseverance,  it  may  be,  in  spite  of 
repeated  failures,  have  at  last  found  out  the  method 
they  now  offer  to  him. 

There  is  a  large  and  rapidly-increasing  class  of 
amateurs  v/ho  devote  some  of  their  leisure  to  working 
in  the  mechanical  and  other  branches  of  practical 
science.  These  persons  will,  it  is  hoped,  in  this 
volume  find  many  things  to  save  them  trouble  and 
speed  them  on  their  way.  Whether  they  want  to 
skeletonize  the  leaf  of  a  plant,  or  to  construct  a 
steam-propeller  for  a  model  boat ;  to  make  a  sky- 
rocket or  an  electric  clock  ;  an  artificial  magnet  or  a 
photographic  handkerchief,  they  will  not  look  in  vain. 
The  tendency  to  the  traditional  in  every  trade  renders 
it  probable  that,  with  persons  of  this  class,  many 
improved  processes  will  originate.  The  amateur 
workman  looks  at  things  with  a  fresher  eye  than  one 
who  has  come  to  regard  the  processes  learned  in  youth 
as  the  finale  of  perfection.  Discoveries  sometimes 
arise  from  the  extension  of  principles  and  methods 
that  have  proved  successful  in  one  department  to 
other  spheres  of  operation.  Bearing  this  in  mind,  it 
is  perhaps  not  to  be  regretted  that  so  few  men  adopt 
as  "  hobby "  the  pursuits  by  which  their  living  is 
obtained.     The  joiner  whose  evenings  are  given  up 


PREFACE. 


to  clockmaking,  the  printer  whose  holiday-time  is 
spent  in  photography,  are  not  to  be  discouraged  as 
perverse.  They  bring  trained  intelligence  to  bear 
upon  fresh  fields,  and  the  stoutest  resister  of  outside 
suggestions  in  his  trade  may  be  the  most  daring 
experimenter  in  relation  to  his  hobby.  Both  classes 
will,  it  is  hoped,  find  something  to  suit  them  in  the 
following  pages. 

In  preparing  for  the  press  the  contributions  of  so 
many  individuals,  a  considerable  amount  of  revision 
and  condensation  has  been  necessary,  and  every 
possible  care  has  been  taken  to  exclude  matter 
already  easily  accessible. 

The  topics  have,  as  far  as  possible,  been  grouped 
together  according  to  their  mutual  relationship ;  but 
as  all  such  attempts  at  classification  are  in  their  very 
nature  defective,  this  arrangement  has  been  supple- 
mented by  a  copious  alphabetical  index. 


TABLE   OF   CONTENTS. 


METRIC   SYSTEM 

I 

MISCELLANEOUS  TOOLS,   INSTRUMENTS,   AND    PROCESSES          3 

CEMENTS  AND   GLUES 

•      79 

VARNISHES   AND   LACQUERS 

.      83 

SOLDERS  AND   SOLDERING    . 

90 

METALS  AND   METAL-WORKING 

92 

STEAM   ENGINE 

.    102 

RAILWAYS  AND   LOCOMOTIVES 

130 

FIRE-ARMS 

.    148 

HOROLOGY       .                .                . 

150 

GLASS                  .... 

175 

WOOD-WORKING 

179 

HOUSE  AND   GARDEN 

184 

DRAWING  AND  MODELLING 

197 

PHOTOGRAPHY 

203 

MUSICAL  INSTRUMENTS 

228 

TAXIDERMY    .. 

234 

PLANT  PRESERVING 

238 

TABLE  OF  CONTENTS. 


.: 

PAGE 

AQUARIA           .                ... 

.        240 

MISCELLANEOUS    CHEMICAL    PROCESSES    AND    COMPOSI 

TIONS        ,               . 

246 

LIGHTING        .               .               .               .               .        .       ' 

262 

DYES                   .               .               . 

265 

WATERPROOFING         .               . 

268 

GILDING  AND  BRONZING       .               .               .               . 

270 

PYROTECHNY 

289 

ELECTRICITY,    MAGNETISM,    AND    TELEGRAPHY  . 

295 

INDEX                ....... 

-^-hZ 

THE    MECHANICS    FRIEND, 


French  Weights  and  Measures,  and  their  English  Equi- 
valents.— The  very  general  use  of  the  metrical  system  in 
scientific  investigations  renders  a  brief  statement  of  it  indis- 
pensable. The  following  will  be  found  sufficient  for  all  ordinary 
purposes  : — 


-Weights. 


Bar  (cubic  metre  of  water) 
Myriagramme 
Kilogramme 
Hectogramme     . 
Decagramme 
Gramme    . 
Decigramme 
Centigramme 


lbs 

5673 

26 

2 


English  Troy  Wdght-. 

z.  dwts,      grains. 


8 
20 

2 

7-4 
1034 

1 5  "434 
1-5434 
015434 


Quadrant  of  meridian 
Degree  centesimal 
Myriametre     . 
Kilometre 
Hectometre    . 
Decametre 
Metre 


II. — Linear  Measures. 

French  Foot. 
=    30784440 


3078444 
30784-44 
3078444      - 
307-8444 
3078444 
3-078444 


English  Foot. 
32809167 
328091-67 
32809-167    . 
3280-9167 
32809167 
32-809167 
3-2809x67 


WEIGHTS  AND  MEASURES. 


French  Lines. 

English  Lines. 

Decimetre 

. 

.      =             44-3296 

47-2452 

Centimetre 

. 

.      =                4-43296 

4-72452 

Millimetre 

.      =               0-443296 

III.— Square  Measures, 

0-472452 

French  Square  Feet. 

English  Square  Feet. 

Myriare 

= 

9476817-46113                     = 

IO764414-3923 

Kilare 

= 

947681 7461 13                   = 

1076441-43923 

Hectare 

= 

94768-1746113                = 

IO7644-143923 

Decare 

= 

9476-81746113 

10764-4143923 

Are 

= 

947-6817461 13           = 

1076-44143923 

Declare 

= 

94-7681746113         = 

107-644143923 

Centiare 

:= 

9-47681746113       = 

10-7644143923 

French  Square  Inches. 

English  Square  Inches. 

Square  deci 

metre 

=             13-646617           = 

15500765 

ft 

French  Square  Lines. 

English  Square  Lines. 

Square  cent 

imetre 

I9-651134 

22-321088 

Square  mill 

imetre 

O-I9651134      = 

0-22321088 

IV. — Solid  Measures. 

The  Stere,  being  a  cubic  metre,  it  follo-ws  that  the  Decastere  is 
equal  to  the  Myrialitre. 
Stere  =  Kilolitre. 

Decistere  =  Hectolitre. 


■v. — Measures  of  Capacity. 

French  Cubic  Feet.  English  Cubic  Feet. 

Myrialitre        .         .         .     =    291-738519             =  353-1714695 

Kilolitre  (or  cubic  metre)     =      29-1738519           =  35-31714695 

Hectolitre        .         .         .     =        2-91738519         =  3-531714695 


Decalitre 

Litre  (cubic  decimetre) 

Decilitre 


French  Cubic  Inches. 
=     504'I24l6o 
=       50-412416 
=        .5-0412416 


English  Cubic  Inches. 
610-2802806 
61-02802806 
6*102802806 


Centilitre 


French  Cubic  Lines. 
=       871-126926 


English  Cubic  Lines. 
1054-5643249 


MFSCELLANEOUS  TOOLS,  ETC. 


Hand  Drilling-Machine. — The  following  machine  answers 


Fig.  2. 


for  all  work,  and  is  said  to  be  nearly  equal  to  steam  power. 
The  machine  is  made  by  E.  &  H.  Widdall, 
of  Beverley,  Yorkshire,  i  is  a  small  hand- 
wheel  ;  2,  a  pair  of  bevel- wheels ;  3  is  a 
stationary  collar  for  pressure-screw  ;  4,  the 
sliding-racks  for  lowering  the  drill ;  5, 
centre  of  drill  bolted  to  shaft.  Fig.  2  is  an 
end  view  of  small  wheel. 

Cork-Boring. — There  are  three  sorts  of 
tools  for  boring  cork  :  the  French  (Dan- 
ger's), a  sharp-edged  steel  cylinder,  fixed 
in  a  handle,  like  a  bradawl,  with  the  cylin- 
der partly  cut  away,  to  get  the  cut  piece 
out.  Mohr's  way  is  to  use  a  tin  tube,  with 
a  milled  rim  at  the  handle  end,  and  the 
pieces  of  cork  push  each  other  out  at  the 
top,  as  in  a  punch.  The  objection  to  this 
(the    cheapest    method)   is    the    welt,    which   can    hardly 


MISCELLANEOUS  TOOLS, 


avoided  in  tin  tubes.  Griffin  prefers  a  brass  tube  filed  to  an 
edge.  All  these  tools  should  be  oiled,  and  turned  round 
while  cutting,  or  they  will  not  make  a  clean  cut ;  when  the  tool 
is  nearly  through,  a  piece  of  cork  should  be  placed  at  the 
back  of  the  piece  you  are  cutting.  The  pieces  cut  out  are 
uninjured,  and  will  do  for  corking  small  bottles. 

Rose-Bit   for   Lathe. — This  rose-bit  may  be  used  in  the 

lathe  or  drilling-ma- 
chine. As  a  counter- 
sink it  works  well. 
The  nose  is  formed 
by   filing  away  to  a  little  below  the  centre,  as  shown. 

Renovating  Files. — The  file  is  to  be  first  cleansed  from  all 
foreign  matter,  and  then  dipped  in  i  part  of  nitric  acid,  3  parts 
of  sulphuric  acid,  and  7  parts  of  water,  the  time  of  immersion 
will  be  according  to  the  extent  the  file  has  been  worn,  and  the 
fineness  of  the  teeth,  varying  from  five  seconds  to  five  minutes ; 
on  taking  it  out  of  the  mixture,  wash  in  water,  then  dip  in 
milk  of  lime,  and  then  wash  off  the  lime,  dry  by  a  gentle  heat 
and  rub  over  equal  parts  of  olive  oil  and  turpentine,  and  finally 
brush  over  with  powdered  coke.  It  is  stated  that  a  new  file  is 
'  improved  by  a  few  seconds'  immersion,  and  also  that  rasps  may 
be  renovated  in  the  same  way. 

To  Draw  Spirals. — A  simple  method  of  drawing  spirals  is : 

AA  is  a  piece  of  wood  of  any  length,  fitted  near  one  end 

with  a  pencil  B  ;   CC  is  a  string  fixed  at  either  end  of  the 

wood,  and  passing 
once  round  the  roller 
D  ;  E  is  placed  at 
the  centre,  from 
which  the  spiral  is 
to  be  described  ;  F 
is  an  extra  point 
to  prevent  turning 
B  round.      As    AA    is 

turned  round  the  roller  D,  the  pencil  will  be  moved  towards 
or  away  from  it,  and  so  a  spiral  will  be  described,  the  pitch 
of  which  may  be  altered  by  varying  the  diameter  of  the 
roller  D. 


n 


V 


e  F 


INSTRUMENTS,  AND  PROCESSES. 


Quickening  Curves. — Spirals,  or  quickening  curves,  as  they 
are  called,  are  made  as  follows  : — 

Draw  a  straight  hne  of  any  length  ;  divide  this  line  into  any 
number  of  equal  parts,  as  shown  in  cut.  Next  divide  one  of 
these  parts  into  halves,  as  at 

o ;  now  divide  with  the  com-  ^,- — -^^ 

passes  (placing  one  foot  upon  /    ,- >>^^  \ 

o),  strike  the  semicircle  12. 
Now  place  the  compasses 
upon  I,  extending  them  to 
2,  and  strike  the  semicircle 

2  3,  but  on  the  opposite  side  """-- --''' 

of  the  line  from   the   other 

semicircle.  Now  return  and  place  the  foot  of  the  compasses 
on  o,  extending  them  to  3,  and  upon  the  opposite  side,  and 
again  strike  the  semicircle  3  4.  Now  return  again  to  i  and 
so  on,  alternately  placing  the  compasses  on  o  and  i,  striking 
the  curve  on  alternate  sides  of  the  line. 


cb:ba::cb:  oe; 


Measuring  Heights  of  Towers,  &c. — Various  modes  are  in 
operation,  but  the  following  will  be  found  simple  and  practical : 

Choose  that  side  of  the  tower  around  which  the  ground  is 
most  level.  Should  an  entirely  level  plain  not  be  obtainable, 
allowance  must  be  e 

made  for  the  in- 
equalities of  the 
surface. 

At  some  distance 
from  the  tower  place 
level  on  the  ground 
a  small  pocket  mir- 
ror, C,  and  recede 
backwards  from  it 
until  the  top  of  the 
tower  E  is  seen 
reflected  in  the 
centre  of  the  mir- 
ror. Then,  as  experimenter's  height  BA  is  to  his  distance 
from  mirror  C,   so  is  the  distance  CD  to  height  of  tower. 

If,  instead  of  a  mirror,  a  trough  of  mercury,  or  even  a  pool 
of  water,  be   employed  for  the  reflection,  the  height  of  the 


MISCELLANEOUS  TOOLS, 


tower  may  be  correctly  ascertained,  provided  the  base  of  it  and 
the  medium  pf  reflection  be  on  the  same  level.  Should  it  not 
be  possible  to  get  a  level  base,  the  difficulty  is  got  over  when 
the  relative  heights  of  the  tower  base  and  the  water  or  mercury 
are  known,  such  difference  having  only  to  be  added  or  subtracted 
when  the  water  or  mercury  is  below  or  above  the  tower's  base, 
as  the  case  may  be. 

Another  method  is  this  :    Measure  out  the.  base  line  AB, 

200  feet  long-,  then, 
erect  a  sliding  staff, 
similar  to  the  sketch 
at  C,  one-twentieth 
of  the  length  of  the 
base  line  from  B, 
which  will  be  ten 
feet.  Then  site  his 
staff  line  BD  in  a 
direct  line  with  E, 
by  raising  or  lower- 
ing the  top  part  of 
the  staff,  as  the 
case  may  be.  Hav- 
ing made  the  other  end  of  the  line  fast  at  B  once  set,  multiply 

the  length  of  BD 
by  20 — that  is,  the 
number  of  times 
the  base  line  is 
divided  into,  which 
will  give  the  exact 
length  of  the  hypo- 
thenuse.  Then  the 
square  root  of  the 
difference  of  the 
squares  of  the  hypo- 
thenuse  and  the 
base  is  the  height 
of  the  perpendicu- 
lar. The  sketch  F 
of  the  sliding  staff 
will  explain  itself. 
Distances  :    How  to  Ascertain. — The  following  plan,  or 


200-Feet- 


INSTRUMENTS,  AND  PROCESSES, 


modification  of  other  plans,  in  use  by  architects   and  others, 
will  be  found  simple  in  application: — 

First  obtain  a  wooden  tooth-powder  box  of  the  size  shown 
by  the  circle,  find  the  centre  by  a  pair  of  compasses ;  then 
draw  the  line  A  a  lit- 
tle below  the  centre 
□,  as  shown.  Next 
mark  on  the  line 
AB  at  an  angle  of 
as     shown. 


22 


2  > 


Next  get  two  slips 
of  silvered  looking- 
glass  of  good  qual- 
ity, but  on  thin 
glass  of  the  respec- 
tive sizes,  B  and  C 
D,  and  nearly  as 
deep  as  the  box 
shown  on  section. 
Fix  the  piece  AB 
by  small  blocks  of 


side. 


wood  glued    or    cemented    on  each 
and  take  care  to  have  them  as  upright  as  possible. 

It  will  be  perceived  the  glass  AB  is  to  be  permanently  fixed 
at  the  angle  shown.  Then  take  the  other  piece  CD,  and  cut 
a  slight  notch  in  the  inner  rim  of  the  box  so  as  to  serve  for  a 
stay,  and  also  as  a  centre  for  this  to  turn  upon  A  at  the  back 
of  this  glass.  Cement  a  thick  piece  of  shoe-sole  leather,  about 
|-  in.  square,  with  a  hole  bored  entirely  through.  In  the  side 
of  the  box  opposite  this,  make  a  corresponding  hole,  and  insert 
a  screw  which  will  embrace  the  leather  at  the  back  of  the  glass. 
The  whole  object  of  this  is  to  adjust  the  glasses  truly,  as  the 
angle  before  given  cannot  be  got  sufficiently  accurate  without 
subsequent  adjustment. 

Having  thus  fixed  your  glasses,  cut  two  gaps  entirely  down  the 
box,  as  shown  at  RV,  and  in  a  line  with  R,  and  perpendicular 
to  A  □,  cut  a  smaller  slit  F  for  the  eyehole.  Now  scrape 
away  neatly  the  silver  from  the  upper  portion  of  AB  down  to 
half  its  depth,  as  shown  in  section,  and  sufficiently  wide  to 
admit  of  seeing  each  side  of  the  hole  R,  when  the  eye  is 
applied  to  the  sht.  Blacken  those  portions  of  the  glass  not 
visible  from  the  eyehole,  as   they  only  tend  to    procure  false 


8  MISCELLANEOUS  TOOLS, 

images,  about  two- thirds  of  C,  and  may  also  be  blackened  from 
D  to  about  F. 

The  instrument  now  merely  requires  to  have  the  lid  put  on, 
premising  that  you  have  first  blackened  every  portion  of  the 
inside  of  it  as  well  as  the  box. 

To  adjust  the  instrument  proceed  as  follows  :— 
Get  three  sticks  or  laths  about  3  feet  long,  find  a  tolerably 
^  level    piece    of   ground,    put 

i    \  in   A,   then    with  a    tape    or 


\ 

\ 


rod  measure  24  ft.,  and  put 

i  \  in  B ;    then  from  B  with  40 

i.  \  ft.  on  the  tape,  and  using  B 

*f  ^.^  as   a   centre  for  the    ring  to 

I  "n  /E  work    upon,    strike    the    arc 

I  \         ^-       /      EF   on    the  ground.     Again 

I  "^^        \^/         return    to    A,    and    with    a 

'^  ""^'^  ~~^'0  radius  of  32  ft.  cut  the  former 

F "        '  arc  with  another  arc  GH,  and 

H  at   the   front    of    intersection 

put  in  your  third  stick.     You  have  now  a  true  square  to  work 

upon. 

Now  measure  off  on  the  line  AC  24  ft.,  and  replace  the  stake 
C  at  that  distance.  You  will  then  have  a  square  whose  sides 
are  equal,  and  whose  angle  is  a  right  angle. 

Place  the  instrument  on  the  stick  B,  and  look  through  the 
upper  part  of  the  glass  AB,  so  as  to  see  the  stake  A.  Next 
turn  the  screw  O  more  or  less  until  the  stake  C  is  just  in  a  line 
with  the  stake  A,  the  one  seen  by  direct  vision,  the  other  by 
double  reflection.  Your  instrument  is  now  adjusted.  Then 
glue  similar  blocks  of  wood  on  each  side  to  retain  it  in  place, 
as  in  the  case  of  AB. 

To  use  it,  proceed  as  follows  : — 

For  vertical  heights,  ascertain  the  height  of  your  own  eye, 
and  mark  upon  the  building  or  spire  this  height,  either  as 
a  line  or  a  white  chalk  dot,  walk  backwards,  still  looking 
directly  through  the  instrument  until  you  see  its  summit,  or 
any  part  you  wish  to  measure,  brought  down  on  the  said  dot 
by  reflection.  You  have  only  then  to  measure  the  distance  of 
your  own  feet  to  the  base  of  the  spire,  and  add  the  height  of 
your  eye  to  it,  and  you  have  the  perpendicular  height  you 
require. 


INSTRUMENTS,  AND  PROCESSES. 


For  horizontal  distances,  say  a  tree  C,  on  the  opposite 
side  C  of  the  river  on  which  you  are  standing,  fix  a 
square  or  cross 
staff  at  A,  and  put 
a  staff  in  the  direc- 
tion of  the  square 
at    B  ;    then,    with 


the    instrument    in 
your     hand,     move 


at  A  □  in  a  direct  hne  until  you  see  the  reflected  image  of  C 
corresponding  with  A  Q.  Then  measure  the  distance  AB, 
and  this  is  equal  to  CA. 

This  instrument  is,  of  course,  held  horizontally  for  the  latter, 
and  edgewaySj  or  vertically,  for  perpendiculars. 

.  Sharpening  Edge  Tools. — The  simplest  mode  of  sharpening 
an  edge  tool  is  to  place  the  cutting  part  in  water  containing 
i-2  0th  of  its  weight  of  sulphuric  or  muriatic  acid;  after  allow- 
ing it  to  remain  there  for  half  an  hour,  wipe  it  gently  with  a 
piece  of  soft  rag,  and  in  a  few  hours  set  in  on-  an  ordinary 
strop.  This  method,  not  generally  known,  is  by  no  means 
new  :  the  effect  of  the  acid  is  to  supply  the  place  of  the 
oilstone,  but  uniformly  corroding  the  entire  surface,  so  that 
nothing  but  a  good  polish  is  afterwards  needed. 

To  Harden  Axles. — To  harden  pattern  axles  with  the 
prussiate  of  potash  of  commerce,  make  the  work  red  hot,  then 
put  on  plenty  of  potash,  and  plunge  in  water ;  or  you  may  get 
some  burnt  leather  or  bone-dust.  You  can  put  a  lot  of  axles 
into  a  wrought-iron  box  ;  put  the  bone-dust  or  leather-cinders 
in,  ram  down  well,  put  some  clay  over  the  top,  build  a  brick 
fire  round  the  box  for  about  three  hours,  then  pull  out,  and 
rinse  in  cold  water ;  this  is  the  case-hardening  process  :  you 
will  find  potash  the  quickest  way. 

To  Temper  Drills  and  Taps. — Heat  them  first  to  a  blood- 
red,  and  then  quench  (this  gives  them  extreme  hardness,  as 
well  as  brittleness),  then,  when  dry,  pour  oil  on  them,  and  hold 
them  in  the  fire,  fixed  in  a  piece  of  iron,  till  the  oil  blazes  off, 
withdrawing  very  frequently  to  watch  the  process.  This  leaves 
a  hardness  that  the  file  will  just  touch. 


MISCELLANEOUS  TOOLS, 


pro- 


Protracting    T -Square. — The  following  sketch  of  a 
tracting  J-square  will  be  found  useful  to  many  : — 

A  and  B  are  the  ordinary  blades,  and  fixed  stock.      C  is  a 

stock     moving     as 


usual  on  the  clamp 
screw-pin  D.  Into 
the  inner  face  of 
this  stock  there  is 
a  semicircle  of 
planetree  (3  J  inches 
radius),  indented, 
which  is  divided 
into  degrees,  and 
figured  from  o  at 
EE'  to  90°.  There 
are  spaces  cut 
through  the  fixed ' 
stock  at  FF' ;  these 
are  sloped  to  the 
centre,  and  laid 
with  planetree,  on 
which  lines  are 
drawn  for  reading 
off  the  degrees  on 
the  semicircle.  G 
G  are  spaces  in  the 
semicircle,  cut  out 
for  the  fingers.  It 
is  useful  for  laying 
down  or  reading  off 
angular  lines,  draw- 
ing polygons  with 
any  number  of 
sides,  shading  at 
various  angles  in 
one  or  two  direc- 
tions. 


To  Temper  Steel  on  one  Edge. — Red-hot  lead  is  an 
excellent  thing  in  which  to  heat  any  long  plate  of  steel  that 
requires  hardening  only  on  one  edge,  for  it  need  not  be  heated 


INSTRUMENTS,  AND  PROCESSES. 


in  any  other  part  but  that  which  is  required  hard,  and  it  will 
then  keep  straight  in  hardening ;  at  least  it  will  keep  very 
much  truer  than  if  it  were  heated  in  the  midst  of  the  ignited 
fuel  of  the  fire. 

Fire-Fan. — This  fan  may  be  applied  to  any  ordinary  fire- 
grate, and  it  is  almost  impossible  to  imagine  its  power.  A 
welding  heat  on 
inch  iron  in  a  com- 
mon fire-grate  may 
be  obtained  by  its 
means. 

The  sides  are 
formed  of  two  pieces 
of  sheet  iron,  the 
bottom  of  w^ood, 
length  I  ft.  3  in.  \ 
the  nose  may  be 
made  6  in.  long, 
breadth  2  in.  ; 
height  61  in.  A 
is  a  wheel  turning 
on  a  loose  spindle, 
with  lock-nuts  for 
the  end,  to  make  a 
centre  for  the  fan- 
spindle  ;  B  is  a 
sheet-brass  pedestal 
moving  on  a  pin, 
with  a  spring  at  the 


bottom  to  keep  the  belts  in  tension  ;  C  is  a  bit  of  iron,  with 
three  arms  riveted  on  to  the  side — the  centre  takes  the  spindle 
H  ;  D  is  a  riveted  arm  to  admit  a  large  hole  being  made  in 
the  side,  and  to  take  a  set  screw  for  the  other  end  of  the  fan- 
spindle  ;  E  the  fan ;  FGI  are  wheels  to  increase  the  revolu- 
tions of  the  fan. 

Hardening  and  Tempering  Tools  and  Weapons. — The 

colour  and  temperature  required  in  hardening  the  above-men- 
tioned articles  are  as  follows :  For  very  soft  temper,  630° 
Fah.,  colour  greenish  blue;  pale  blue,  610°  Fah.,  for  saws, 
the  teeth  of  which  are  set  with  pliers  ;  blue,  590°  Fah.,  for 


12  MISCELLANEOUS  TOOLS, 

large  saws;  dark  blue,  570°  Fah.,  for  small  fine  saws;  dark 
purple,  550°  Fah,,  for  soft  swords  and  watch-springs;  light 
purple,  530°  Fah,,  for  ordinary  swords  and  watch-springs; 
very  pale  purple,  520°  Fah,,  for  table-knives  ;  brown  yellow, 
500°  Fah.,  for  adzes  and  plain  irons;  clay  yellow,  490°  Fah., 
for  chisels  and  shears ;  dark  straw,  470°  Fah.,  for  penknives  ; 
dark  yellow,  470°  Fah.,  for  razors,  &c.;  pale  straw,  430°  Fah., 
for  lancets,  &c. 

On  Grindstones.  —  Discard  every  contrivance  for  fixing 
tools  on  the  grindstone ;  they  are  one  and  all  eminently  un- 
practical. A  grindstone  will  not  do  nice  work  unless  it  is  kept 
true,  and  fixing  the  tool  against  it  will  of  course  wear  it  away 
unevenly.  Tools  should  always  be  traversed  across  the  face  of 
the  stone,  and  when  a  flat  surface  is  to  be  ground  by  a  circular 
stone,  it  is  clear  that  this  traverse  must  not  be  exactly  straight 
across  it,  or  the  bevel  will  be  hollow.  A  very  slight  hollow  is 
perhaps  rather  an  advantage  than  otherwise  in  such  tools  as 
chisels  and  plane-irons  for  wood ;  but  there  are  numerous 
cases  where  the  face  should  be  ground  as  flat  as  possible. 
This,  as  just  stated,  cannot  be  accomphshed  by  keeping  the 
tool  fixed  against  the  stone.  Turning-gouges,  again,  must  be 
continually  swept  round  in  a  semicircle  on  the  stone  if  the 
proper  form  is  to  be  obtained ;  and,  whatever  the  tool  may  be, 
it  should  be  continually  traversed  if  the  figure  of  the  stone  is 
to  be  preserved,  which  is  a  matter  of  the  first  importance 
where  accuracy  in  the  angles  of  the  edges  is  aimed  at.  It  is 
true  that  some  workmen  have  a  knack  of  producing  wonderful 
edges  on  stones  that  iTin  like  eccentrics  ;  but  this  is  a  rare 
gift,  and  the  bad  state  of  the  stones  in  many  large  workshops 
has  much  to  answer  for  in  the  very  indifferent  character  of  the 
metal-turning  to  be  found  in  them.  Where  all  run  to  one 
stone,  few  take  any  care  of  it,  and  it  becomes  almost  a 
practical  impossibihty  to  grind  up  a  shde-rest  tool  with 
anything  like  the  accuracy  required  for  first-class  toolwork. 
Regular  grinders,  however,  know  the  value  of  a  true  stone,  and 
are  very  careful  in  keeping  them  so.  A  true-running  stone 
with  a  good  face  will  make  the  workman  independent  of  any 
rests  and  holders  beyond  his  own  arms  and  hands.  It  is  true 
that  goniostats  are  used  for  very  fine  and  delicate  tools  where 
extreme  accuracy  of  form  is  essential ;  but  these  are  generally 


INSTRUMENTS,  AND  PROCESSES. 


13 


ground  on  laps  running  horizontally  and  presenting  a  plane 
grinding  surface. 

For  amateurs'  use  nothing  is  better  than  a  treadle  grind- 
stone about  20  in.  or  24  in.  in  diameter ;  and  if  the  tools  are 
always  traversed  on  it,  and  it  is  never  allowed  to  lie  in — or 
even  over — water,  it  may  be  reduced  2  in.  or  3  in.  diameter 
by  honest  work,  before  it  requires  turning  up  again  ;  and  the 
operator  will  find,  that  when  he  has  accustomed  himself  to 
grind  true  by  hand  alone,  he  will  seldom  want  even  a  rest, 
and  would  certainly  never  think  of  spoiling  his  stone  by  using 
such  an  awkward  and  unpractical  contrivance  as  a  fixed 
holder. 


Saw-Benches. — The  following  plan  of  a  saw-bench  will 
suit  any  possessor  of  a  kthe.  The  box  ABC  rests  on  the  bed 
of  the  lathe,  and  is  kept 
in  position  by  the  tenon 
D  fitting  the  lathe-bed, 
and  fastened  by  the  nut 
and  screw  EF.  The  plat- 
form G  is  hinged  at  the 
back  to  C,  and  in  front  is 
fixed  by  the  three  tenons 
of  A —  shown  by  dotted 
lines — and  the  hook  H. 
I  is  the  guide  for  the  wood 
while  being  sawn,  and 
which  is  always  retained 
parallel  to  the  saw  by  the 
parallel  movement  JK  ; 
it  is  secured  by  the  nut 

M  working  in  the  slot  N.  The  circular  saw  works  through 
the  groove  O.  This  is  a  very  simple  and  cheap  method  of 
mounting  a  circular  saw ;  but  a  vertical  machine  is  more 
convenient,  as  the  friction  is  less. 

The  top  plate  should  be  about  18  in.  long  by  12  in.  broad, 
the  spindle  about  1 8  in.  long  by  3  J  in.  thick ;  the  small 
pulley  3  in.  large,  wheel  about  30  in.  in  diameter  and  weighing 
about  56  lbs.  You  can  determine  the  height  of  the  bench  by 
the  wheel,  which  should  work  freely. 

A  is  the  edge  of   the    iron  plate.     B   and    C    the    centre 


14 


MISCELLANEOUS  TOOLS, 


screws    for    the    spindle  to  run    on,    with    nuts    to    lock    the 
screws  tight ;  the  sockets  can  be  of  cast  iron  for  cheapness,  and 

must  be  screwed 
oa  the  plate  from 
the  front,  which 
must  be  counter- 
sunk. D  is  one  of 
the  sockets  with  the 
two  screws.  E  and " 
F  are  the  nut  and 
centre  screw  ;  the 
point  must  be  of 
hard  steel.  G  is 
the  saw  and  spin- 
dle, which  should 
be  made  of  iron, 
with  the  ends  drill- 
ed out  cone  shape 
to  fit  the  screws. 
H  is  the  iron  plate 
with  the  slot  for 
the  saw  to  run  in, 
which  must  be 
3-i6ths  of  an  inch 
thick,  and  firmly 
screwed  to  the 
bench.  I  is  the 
guide  made  of  wood 
9  in.  long,  with 
even  face.  J  is 
one  of  the  thumb- 
screws with  which  to  fasten  the  guide  |-in.  screw. 


B                  III' 
il 

1           jll 
1 

1 
1 

!     |[ 

1 

^                   lllii 

1  1 
1 

j    1 

B        i    J 

Fret-Saws. —  i.  The  following  is  run  at  a  speed  of  from 
300  to  500  cuts  per  minute,  and  the  length  of  stroke  of  the 
saw  is  regulated,  as  will  be  seen  in  the  drawing.  When  circles 
are  required  to  be  cut,  adjust  a  clamp,  with  centre  pin,  to 
the  saw-table,  and  set  it  to  the  required  radius. 

A,  disc,  with  adjustable  crank-pin  for  regulating  the  throw 
or  length  of  cut.  B,  saw-table  on  a  pivot  C,  and  fixed  by 
thumb-screw  D.     E,  saw  held  in  screw  jaws.    F,  slide  caj.-r>'ing 


INSTRUMENTS,  AND  PROCESSES. 


15 


the  elbow  lever,  and  fixed  by  a  set  screw  behind.  GG, 
grooved  pulleys.  H,  stretching  band  of  crinoline  steel,  kept 
in  tension  by  the 
slide  F. 

2.  This  fret-and- 
scroU  saw  is  con- 
structed on  the  fol- 
lowing principle  : — 

A  is  the  driving 
shaft  which  carries 
a  fly-wheel  B,  a  ,= 
fast-and-loose  pul- 
ley CD,  and  on  the 
end  of  the  same 
shaft  B  is  a  disc  crank  E.  F  is  a  connecting  rod  which 
communicates    the    motion    to    a    slide-block    G.      At    each 

end  of  the  block  G 

•     £     J  TT  r «  G.I  .  r  I  G .  a  . 

IS   fixed   a  rope    H 

and  I,  which  trans- 
mit the  action  to 
two  other  slide- 
blocks  K  and  L, 
between  which  the 
saw-blade  is  fixed. 
MNOP  are  four 
guide  pulleys  for 
the  ropes.  Q  is  a 
hand-wheel  keyed 
on  a  lifting  "screw 
R,  which  screw  goes 
through  a  nut  on 
which  the  pulley  P 
is  bolted  fast ;  by 
this  contrivance  the 
saw-blade  is  tight- 
ened or  slackened. 
S  is  a  pin  on  which 

the  table  T  is  centred ;  on  its  bottom  side  is  fastened  a 
segment  U,  to  change  it  to  any  angle  required.  V  is  the  belt 
guard. 

3.  A  vibrating  fret- saw.     Fig.   i   is  a  side  view  of  the  in- 


i6 


MISCELLANEOUS  TOOLS, 


ternal  arrangement  of  the  working  parts.  A  is  a  flexible  piece 
^ij.  I  of  wood  strong  enough 

to  keep  the  saw  B 
tight,  lancewood  or 
ash  would  do  ;  it 
must  be  firmly  fixed 
by  the  thick  end  to 
the  frame ;  B  is  a 
fine  saw ;  C  is  the 
table-top,  made  of 
ij-in.  birch,  with  a 
small  hole  in  it  for 
the  saw  to  work 
through ;  DD  are  two 
V-faced  guide  brack- 
ets screwed  to  under- 
side table  and  hav- 
ing a  corresponding 
guide-piece,  working 
betwixt  them,  to  the 
top  end  of  which  is 
attached  the  saw,  and 
the  bottom  end  the 
rod,  connecting  it  to 
a  crank  on  the  face 
of  wheel  E.  It  may 
be  made  with  slot  to 
alter  the  stroke  to 
'-'    length  of  saw  used. 

F  is  the  driving  wheel,  worked  by  a  crank  with  rod  G  and 

pedal  H.     Fig.  2  is  a  frame. 

Brazing  Band-Saws. — In  fig.  i,  G,  a  large  cast-iron  cramp 
to  hold  the  saw  while  brazing  it,  is  3  ft.  6  in.  long,  a  foot 
deep,  and  3  in.  wide.  It  is  made  hollow  to  allow  the  bolts 
AAAA  to  pass  through  the  surface  P.  There  is  an  open  side 
left  to  get  over  this  difficulty.  M  is  the  foot  for  resting  on  the 
bench  ;  TT  are  two  bolts  for  holding  it  to  the  bench.  O  is  a 
recess  planed  in  the  surface,  of  \  in.  wide,  3y\-  in.  deep,  for  lay- 
ing the  saw  in,  so  that  it  just  comes  level  with  the  surface. 
PK  represents  a  vacancy  for  the  tongs ;  it  should  be  made 


T^ 

^^^^ 

1 

1 

J 

^=^^^^ 

1 

^^^ 

INSTRUMENTS,  AND  PROCESSES. 


17 


J-in.  square  iron  to  pass    nicely 


just  low  enough  to    admit 

between    the    saw    Y 

and    the    bottom    of 

the    recess    A.     You 

must  place  the  open 

side     of     each     iron 

cramp  opposite  to  the 

way  in  which  you  are 

standing.     That    will 

then  bring  the  recess 

O  close  to  you,  when, 

placing  the  saw  Y  on 

the    cast-iron    cramp, 

you  will  have  the  teeth  towards  you,  and  the  blank  part  of  the 

saw  will  rest  against  the  shoulder  of  the  recess  O.     You  can 

let  it  lie  on  the  ground  when  the  bolt-cramp  AAAAAA  has 

got  hold  of  the  saw  Y.     The  tongs  used  require  to  be  7^-in. 

square  iron,  and  to  come  close  together.     A  second  pair   of 

tongs  are  also  required  ;   they  must  fit  nice  and  close,  and  must 

be  7^  in.  wide  and  \  in. 
joint  after  the  hot  tongs 

cool  it. 

end  of  the  brass,  and  taper  it  down  to  nothing.  After  that, 
bring  the  filed  ends  over  the  vacancy  K,  one  end  over  the 
other,  put  some  spelter  and  borax  in  between,  and  then  screw 
the  saw  Y  down  with  bolt-cramps  AAAAAA.  Now  everything, 
is  ready  for  brazing,  get 
your  tongs  a  white  heat,  fK.2.    s 

put  them   over  the  joint,  a  _^^n(r     a 

open,  just  to  see  how  the 
brass  is  going  on  ;  when 
the  blue  flare  rises,  the 
brass  has  melted,  and  get 
someone  to  put  the  second 
pair  ©f  tongs  on,  when 
you  can  take  the  others 
away.  Then  loosen  the 
bolts,  cramp  the  joint  from 
over    the    vacancy,     and 

bring  it  farther  up  the  recess  O.       Now  it  must  be  screwed 
down  tight,  and  filed  down  to  a  uniform  thickness,  and  you 

B 


thick  ;   they  are  for  laying  hold  of  the 
to  keep  it  well  together,  and  also  to 
When  commencing  to  braze,  file  |  of  an  inch  off  each 


i8 


MISCELLANEOUS  TOOLS, 


will  find   a  good   strong  joint ;   smooth,  file,  and   emery  the 
joint,  so  that  it  will  slip  through  the  wood. 

Fig.  2. — A  side  view  of  one  of  the  iron  cramps.  The  dog 
Q  is  hollowed  out  in  the  centre,  just  leaving  each  end  a  little 
thicker.  O  is  a  fly-nut,  H  a  bolt  to  pass  through  the  surface 
of  cast-iron  cramp.      O  is  \  in.  wide,  3  in.  long. 

Fig.  3  shows  the  end  of  cast-iron  cramp,  and  how  the  taper 
can  be  filed  at  G.  By  screwing  the  bolts  on  to  the  saw  you 
can  hold  it  tight  while  you  file  it,  which  you  will  find  a  great 
advantage.      In  the  plan,  O  is  merely  the  file. 

Sawing-Machine. — The  saw-frame  ABCD  has  a  central 
wooden  rod  EF,  and  a  saw-blade  G  and  H  on  each  side,  which 
are  stretched  by  nuts  and  screws  at  ABCD  in  the  usual  way. 
The  saws  are  guided  perpendicularly  by  the  fixed  rods  IJKL  ; 

these  pass  through  holes 
in  the  cross  heads  of  the 
saw-frame  AB  and  CD. 
The  saw-frame  is  suspen- 
ded from  the  steel  bow- 
spring  M,  attached  to  the 
column  N  erected  at  the 
back  of  the  bench,  and 
which  serves  to  support 
O  and  P,  in  which  the 
upper  guide  -  rods  are 
fitted  ;  the  lower  end  of 
the  saw-frame  is  con- 
nected by  the  hook  Q 
with  the  treadle  R. 

For  straight  cuts  a 
wfde  saw  H  is  used, 
and  the  wood  is  guided 
against  the  square  fence 
S,  which  overlaps  the 
front  edge  of  the  bench, 
and  is  fixed  by  the  bind- 
ing screw  T  passing 
through  a  groove  in  the  fence  S.  For  circular  pieces  a  narrow 
saw  G  is  employed,  and  an  adjustable  centre  point  U,  fast- 
ened by  the  nut  V,  and  working  in  the  stationary  bar  P,  serves 
as  an  axis  of  motion  for  the  piece  of  wood  to  be  tuc. 


INSTRUMENTS,  AND  PROCESSES. 


In  order  to  have  the  bench  unobstructed,  so  that  large  pieces 
may  be  sawn,  the  guide-rods  IJKL,  upon  which  the  saw-frame 
works,  are  discontinuous,  the  lower  pair  only  reach  from  the 
under-surface  of  the  work-bench  to  WX  ;  while  the  upper  pair 
are  fixed  to  the  two  cross  pieces  O  and  P  attached  to  the 
column  N. 

The  saws  are  kept  steady  by  running  in  the  saw-kerfs  Y 
and  Z,  in  the  lower  rail  P  of  the  guide-frame.  The  saw  H  is 
represented  cutting  a  straight  plank,  and  the  saw  G  a  circular 
piece. 


Magnetic  Lock. — This,  which  is  known  as  "  Nobody's 
lock,"  is  without  keyhole,  with  changeable  key,  and  is  useless 
to  all  but  the  owner.  It  should  be  made  of  brass,  or  some 
non-magnetic  metal  (the  harder  the  better) ;  the  four  circular 
metallic  pieces,  having  the  adjustable  magnets  centred  rather 
tightly  on  them,  are  suspended  on  pivots,  which  allow  of  rota- 
tion with  sufficient  ease,  and  have  each  a  groove  (as  seen) 
nearly  to  the  centre,  to  admit  the  four  prongs  of  the  bolt  (in 
unlocking),  and  the  whole  nicely  balanced.  There  being  no 
springs,  and  the  bolt  only  required  to  slide  easily,  the  handle 
must  be  allowed  to  turn  in  its  centre  when  the  force  used  would 
exceed  what  is  necessary  for  the  sliding  of  the  bolt.  This  is 
necessary  to  pre- 
vent injury  to  the 
pivots  of  four  cir- 
cular pieces.  These 
details,  and  some 
others,  are  not 
shown,  as  they  will 
be  readily  under- 
stood. In  the  il- 
lustration, however, 
the  hole  is  dotted 
as  square  for  the 
sake  of  greater  sim- 
plicity. 

Lock  shown  com- 
plete, and  the  small 
handle  ready  to  be  turned,  for  withdrawing  the  bolt  when   the 
key  (as  set)  is  applied. 


20 


MISCELLANEOUS  TOOLS, 


Key  shown  disarranged  in  a  manner  suitable  for  the  conser- 
vation of  magnetism,  and  being  so  applied  to  the  lock  (after 
the  bolt  is  protruded  by  means  of  the  handle)  produces  a  like 
arrangement  in  the  lock  and  the  effect  of  locking. 

Lock    with  front 
^^^^  _-^-^     ^^^      _,  plate    removed     to 

exhibit  the  interior 
mechanism,  where 
the  key,  being  sup- 
posed to  be  ad- 
justed over  the  right- 
hand  end,  has  rotat- 
ed the  magnets  to 
I  the  proper  position, 
enabling  the  bolt  to 
be  withdrawn  by 
^1  turning  the  handle. 
Key  shown  ready 
set  by  owner  to  turn 
over  upon  its  proper 
place  on  the  lock,  so  as  to  cause  the  rotation  of  magnets  as 
required  to  enable  the  bolt  to  be  withdrawn.  In  the  owner's 
memory  the  key  would  be  set  thus  :  4J,  3!, 


4- 


Improved  Screw-Driver  for  large 
Screws. — This  tool  possesses  very 
great  advantages  over  the  common 
ones,  in  consequence  of  its  being 
worked  by  a  lever,  and  having  a  re- 
volving top.  It  is  especially  suitable 
for  wheelwrights,  railway-carriage  build- 
ers, roof-makers,  and  will  turn  out  twice 
as  much  work  as  the  old  ones.  The 
following  is  a  description  :  A  is  the 
point  of  the  tool ;  B  is  the  lever,  which 
can  be  made  to  fold  up  (when  not  in 
use)  at  the  joint,  as  shown  in  the  cut. 
The  dotted  lines  near  the  joint  are  the 
four  squares  upon  which  the  lever  fits, 
and  while  in  this  position,  you  draw  it  to  you,  then  lift  it  up 
clear  of  the  square  part,  and  on  to  another,  and  so  on.     C  the 


INSTRUMENTS,  AND  PROCESSES. 


head,  is  the  same  as  a  common  brace-head,  which  you  keep  to 
your  shoulder.  The  head  should  be  made  of  wood,  and  the 
other  part  of  steel. 

Improved    Hand-Press. — Below     is    an    adaptation     for 


stronger  work  of 
By  it  you  may 
punch  holes  ^  by  i 
thick  and  larger, 
by  simply  pressing 
the  lever  down.  In 
fig.  I  is  a  side 
view,  fig.  2  a 
front  view,  and  fig. 
3  section  showing 
the  working  parts. 
A  is  the  body  ;  B, 
eccentric  lever  ;  C, 
steel  pin  ;  D,  steel 
spindle  at  top  ;  E, 
punch ;  F,  releaser; 
G,  bed  for  punch ; 
HH,  two  set  pins 
for  same  ;  I,  weight 
if      required ;      J, 


the     presses     for    stamping    on    paper. 


22 


MISCELLANEOUS  TOOLS, 


lever ;  K,  peg  to  fit  groove ;  L,  to  keep  spindle  steady ; 
M,  powerful  spring  to  lift  spindle  up  and  release  iron  of  the 
parallel  nipple   or  punch.       This  compact  little  press  would 


be  very  useful  to  many  to  whom  a  large  one  would  be  too 
cumbersome  for  light  work. 


Cleaning  Lenses. — Neither  wash-leather  nor  silk  will  answer 
after  being  handled.  A  roll  of  soft  blotting  paper  put  in  a  case 
to  keep  the  hands  from  it  is  the  best ;  velvet  is  also  very  good. 


INSTRUMENTS,  AND  PROCESSES. 


23 


Stud-Box  and  Wrencli. — A  capital  stud-box  with  wrench 
can  be  made  on  the  accompanying  plan. 


Alloy  for  Journal-Boxes. — The  following  alloy  has  been 
found  to  answer  excellently  for  journal-boxes  :  4  lbs.  antimony, 
12  lbs.  of  tin,  and  12  lbs.  of  copper.  Having  melted  the  copper, 
add  the  tin  and  afterwards  the  antimony.  It  should,  after 
having  been  run  into  ingots,  be  cast  in  the  form  required  for 
the  box. 

Leakage  in  Smoke-Box. —  Insert  in  the  end  of  tube  a  drift 
4  in.  or  5  in.  long,  turned  to  fit  the  tube,  slightly  tapered  and 
hardened  :  two  or  three  sharp  blows  on  this  will  suffice  ;  then 
run  round  with  small  caulking  tool.  If  a  bad  leak  in  fire-box 
end,  better  take  out  tube  as  follows  :  Remove  ferrule,  chip  off 
end  of  tube  level  with  plate  in  fire-box,  then  with  a  drift 
(turned  with  a  shoulder  a  little  less  than  outside  diameter  of 
tube)  drive  it  out  from  fire-bpx  end,  remove  slate  and  scale, 
anneal  ends,  and  replace  (end  to  project  in  fire-box  about  \  in.), 
then  drift  as  above.  The  ferrule,  if  not  too  thin,  may  be 
drawn  a  little  larger,  or  replaced  by  a  new  one.  If  properly 
forged  it  will  require-  no  turning.  Having  driven  the  ferrule 
home,  the  end  of  tube  may  be  riveted  over  to  the  plate  ;  ferrules 
are  unnecessary  at  smoke-box  end.     A  dolly,  or  piece  of  iron  to 


24 


MISCELLANEOUS  TOOLS, 


hold  on  drifts,  long  enough  to  clear  fire  and  smoke  box  doors,  is 
necessary. 

An  Adjusting  Carrier. — Here  is  a  sketch  of  an  adjusting 

carrier  contrived 
by  a  workman  in 
the  employ  of 
Messrs  Holtzapffel. 
It  is  capable  of 
holding  anything 
from  \  in.  up  to  i  in. 
diameter. 

AAA  is  the  front 
view,  B  the  edge ; 
they  are  made  either 
in  gun-metal,  iron, 
or  steel  ;  CCC  to 
the  dotted  lines  are 
one  and  the  same 
pieces ;  DDDD 
are  separate  pieces 
fitted  to  CCC  at  the 
bottom  by  screws 
EE,  and  at  the  top 
by  screws  FFF, 
which  fit  into  a  re- 
volving steel  nut 
GGG,  the  faces  of 
the  screws  binding 
upon  the  faces  of 
the  nuts  and  the 
faces  of  DDDD,  at 
^  one  and  the  same 
time,  just  sufficient- 
ly tight  to  allow 
of  the  nuts  revolving  uniformly,  carriering  the  binding  or 
clamping  screws  HH  with  it,  the  head  of  H'  clamping  the 
smaller  diameter  J  and  the  end  H^  By  this  arrangement, 
it  will  be  observed,  that  anything  from  1  in.  to  i  in.  dia- 
meter may  be  clamped  without  much  loss  of  time  in  adjusting 
the    binding    or    clamping    screw    HH    upon    the   material 


INSTRUMENTS,  AND  PROCESSES. 


2S 


by    turning   round     H    into    H%   the    position    of,    and    vice 
ve7'sd. 


Matrices  for  the  Paper  Pro- 
cess of  Stereotyping. — The  fol- 
lowing is  the  process  for  making 
the  mould  for  casting  stereo- 
plates  by  paper  :  Take  a  sheet 
of  tissue  paper,  and  having  laid 
it  on  a  perfectly  even  surface, 
paste  on  to  it  a  soft  piece  of 
printing  paper,  pressing  it  evenly 
on  to  the  tissue.  Then  lay  the 
paper  on  the  type  form  (which 
must  be  oiled),  cover  it  with  a 
damp  rag,  and  beat  the  paper 
in  evenly  with  a  stiff  brush  ; 
then  paste  a  piece  of  blotting, 
and  repeat  the  beating-in  ;  then 
in  a  similar  manner  paste  about 
these  more  pieces  of  tough 
paper,  and  back  up  with  car- 
tridge paper.  Dry  the  whole 
with  a  moderate  heat,  under 
slight  pressure.  When  it  is 
dried,  brush  it  well  over  with 
either  French  chalk  or  black- 
lead,  and  the  matrix  will  be 
ready  for  use. 


New  Style  of  Pin. — The  phrase  "  pin-money  "  is  to  us  of 
modern  days  a  meaningless  term,  but  if  we  go  back  to  the 
time  when  the  expression  originated  w^e  find  it  had  a  painful 
significance,  for  prior  to  the  introduction  of  the  machinery  for 
their  manufacture  a  pin  made  by  hand  w^as  in  value  a  synonym 
for  a  penny.  Ex- 
travagance in    the^^^^^^^^--— --.^^__  _^=_=^<<i'^ 

use    of  pins    at  the  lU-yitf*^-^^^^"  -      »,.-—«  -  i .    .     aiaaa^i^ 

present  day  is  in- 
credible.    The  annexed  engraving   shows  a    new  pin,  which 
will  remain  in  position  when    once    placed,   and    not    injure 


26 


MISCELLANEOUS  TOOLS, 


PPENCH 

NAIL. 


the  fabric.  The  improvement  is  in  forming  the  shank  with 
one  or  more  swells  or  enlargements,  beginning  at  or  near  the 
point,  and  terminating  in  square  or  bevelled  shoulders  ;  or  if 
designed  to  be  permanently  placed,  as  in  fastening  papers 
together,  the  expanded  portion  is  provided  with  barbed  points, 
so  that  if  once  inserted  it  cannot  be  withdrawn. 

French  and  English  Nails  compared. — A  writer,  assert- 
ing   the    superiority    of  French    over    English    nails,    says  : 

"The  fault  of  the  Eng- 
lish nails  is  their  being 
made  in  the  shape  of  a 
wedge,  which  detracts  from 
their  holding  power  and 
makes  them  more  likely 
to  split  the  wood.  The 
French  nails  are  the 
same  thickness  all  the  way 
down,  and  have  a  sharp 
point,  which  is  an  im- 
provement that  the  Eng- 
lish makers  seem  to  think 
quite  unnecessary.  The 
French  nails  are  made  of 
wire,  they  are  less  brittle 
than  the  English,  and  can 
be  used  over  and  over 
again  without  breaking. 
French  nails  have  another 
great  advantage,  which  is 
this,  when  an  English 
nail  is  drawn  out  of  its  hole 


to    a  certain  extent,  it  (owing  to  its  wedge  shape)  loses   all 
power  of  holding,  whereas  the  French  nail  holds  to  the  last." 

Drilling-Machines. — Of  late  years  much  of  the  harder  part  of 
mining,  excavating,  &c.,  is  performed  by  machinery;  a  descrip- 
tion, therefore,  of  the  principal  instruments  in  use  for  that 
purpose  will  not  be  without  interest  to  our  readers.  First  we 
have  the  drilling-machine  patented  by  Mr  Newton.  The 
invention  relates  to  machines  in  which  the  working  parts  and 
bed  are  attached  to  an  upright.     The  feeding  of  the  drill  is 


INSTRUMENTS,  AND  PROCESSES.  27 

produced  by  a  weight  applied  directly  to  the  drill-stock,  regu- 
lated by  an  adjustable  counterpoise  connected  to  the  drill- stock 
by  a  system  of  levers,  which  also  raise  the  stock  and  drill 
above  the  work,  to  permit  of  the  adjustment  and  removal  of 
the  work  from  the  drilUng  bed  ;  and  it  is  in  this  counterpoise 
and  system  of  levers  and  their  connections  that  the  first  part 
of  the  invention  lies.  The  second  part  of  the  invention  con- 
sists of  a  bracket  attachment,  which,  with  the  bearings  in 
which  the  drill-stock  works,  are  all  cast  in  one  piece  and 
bolted  to  the  standard.  The  third  part  consists  in  furnish- 
ing the  adjustable  bed-plate  with  a  fixed  jaw  and  a  sHding  jaw 
which  works  in  fixed  guides  on  the  bed,  and  is  adjustable  by 
a  screw  for  clamping  the  articles  between  the  two  jaws.  The 
operation  consists  finally  in  constructing  the  standard  and  bed- 
plate with  a  recess  for  the  introduction  of  large  articles,  with- 
out having  the  drill-stock,  or  the  table  or  bed-plate,  set  out  at  a 
great  distance  from  the  face  of  the  standard. 

Drilling  Holes  in  Glass,  &c. — A  practised  man 
gives  it  as  his  experience  that  a  splinter  of  a  diamond 
is  the  best  article  with  which  to  drill  holes  in  glass. 
The  splinters  are  mounted  as  in  the  diagram.  A,  brass 
wire,  is  made  to  fit  drill-stock,  sawn  down  a  little  way 
with  a  notched  knife  to  allow  the  splinter  to  fit  tight ; 
B,  the  splinter  of  stone  cemented  by  heat  with  a  little 
shellac  or  sealing-wax.  The  drill  is  to  be  used  quite 
dry  and  with  care. 

Rock-Drilling  Machinery. — An  improved  drill  has  been  in- 
vented by  Mr  Christian  Jurgens,  of  Weber  Creek,  California, 
which  consists  of  three  angular  cutting  bits,  having  an  obtuse 
point,  thus  giving  it  three  regular  inclined  faces  and  three 
corners.  When  the  drill  has  become  worn  and  dull  from  use, 
the  inventor  uses  a  die,  by  means  of  which  the  smith  may 
more  readily  and  perfectly  restore  the  drill  to  its  original  shape. 
In  forming  the  original  drill,  the  inventor  uses  a  swage  block, 
into  which  the  bar  of  metal,  after  being  heated,  is  placed  hori- 
zontally, where  it  is  hammered  and  turned  until  properly  shaped 
to  receive  its  cutting  faces  and  points.  This  swage  may  be 
also  advantageously  used  in  repairing  drills,  and  in  keeping 
the  drill  in  proper  shape  as  it  is  gradually  worn  up  by  use  and 
the  requirements  of  new  cutting  edges.      By  the  use  of  these 


28  MISCELLANEOUS  TOOLS, 

shaping  tools  a  drill  may  be  more  perfectly  and  readily  shaped 
and  sharpened  than  in  the  ordinary  manner  of  hammering  on 
an  anvil. 

Alley's  Drilling-MacMne. — This  instrument  was  introduced 


by  Messrs  Neilson  Brothers  of  Glasgow,  and  was  designed  by 
Mr  S.  Alley  of  that  firm.     Its  chief  peculiarity  is  that  nearly 


all  the  gearing  is  enclosed  within  the  hollow  pillar  and  radial 
arm,  thus  protecting  it  from  the    dust  and  from  contact  with 


/  'sgyw  'lira  xn^risaHD 

INSTRUMENTS,  AND  AS?S8I3.  ^031^^   NOXgOJ 

surrounding  objects,  whilst  the  tool  as  a  whole  is  rendered  very 
compact.  The  pillar,  which  is  of  the  telescope  form,  is  raised 
and  lowered  by 
hand  in  the  smaller 
machines,  but  for 
larger  sizes  an  ar- 
rangement repre- 
sented in  the  sec- 
tional view  is  adopt- 
ed. The  wheel  and 
screw  on  the  top  of 
the  vertical  pillar  on 
the  left  -  hand  side 
of  the  main  pillar  is 
employed  for  rais- 
ing a  coupling  on 
the  driving  shaft, 
by  which  means  the 

lifting  screw  is  coupled  to  it.  The  drill-spindle  is  provided 
with  a  self-feeding  motion,  which  can  be  engaged  and  dis- 
engaged at  plea- 
sure by  means  of 
a  friction  -  clutch. 
The  other  parts  of 
the  machine  are 
so  clearly  shown 
in  the  woodcut 
that  a  further  de- 
scription is  not  re- 
quired. 

Boring-Machine. 

— The  following 
boring-machine  is 
to  be  used  where 
great  power  is  ne- 
cessary :  A  is 
a      stand       which 

supports  the  flywheel  B.  A  cogwheel  C  revolves  on  the 
same  axle  as  this  flywheel,  and  turns  another  cogwheel  D, 
which  revolves  on  a  pivot,  to  which  is  attached  the  auger  E. 


30  MISCELLANEOUS  TOOLS, 

The  flywheel  is  turned  by  the  treadle  and  crank  H.  This 
would  give  sufficient  power  to  the  auger  to  bore  through  the 
thickest  planking. 

Pillar    Drilling-Machine. — This    compact  and   useful  in- 


strument occupies  a  space  of  less  than  2  ft.  square,  the  height 
being  only  5  ft.  3  in.      It  can  be  worked  as  advantageously  by 


INSTRUMENTS,  AND  PROCESSES. 


31 


steam  as  by  manual  labour.  When  worked  by  the  latter,  the 
pressure  on  the  drill  is  produced  by  the  feet,  leaving  both 
hands  at  liberty  to  hold  the  work  and  turn  the  machine.  On 
removing  the  foot  the  drill  is  instantaneously  lifted  out  of  its 
work ;  the  pillar  being  accurately  turned,  the  table  is  easily 
adjusted  to  any  depth,  so  as  to  take  in  articles  not  exceeding 
2  ft.  3  in.  in  height.  This  pillar  drilling-machine  requires  only 
one  person  to  work  it.  The  drill  makes  two  revolutions  to  one 
of  the  hand-wheel,  consequently,  for  holes  up  to  |  in.  diameter, 
it  will  drill  two  to  one  of  any  other  machine,  and  when  worked 
by  steam  power,  it  retains  this  advantage  up  to  f -in.  holes. 

Boring-Tools. — There  are  several  boring-tools  for  wheels, 
&c.,  to  follow  up  drills,  or  to  finish  holes  left  in  the  castings. 
The  rose-bit  is  of  very  general  use  in  boring  out  brasses 
for  bearings.  It 
is  made  of  steel 
turned,  filed  into 
teeth,  and  harden- 
ed. Fig.  I  repre- 
sents two  forms. 
Fig.  2  is  the  regu- 
lar boring-bit  of 
engineers  ;  it  is  a  semicircular  bit  of  hard  steel  shown  more 
plainly  at  B  ;  the  other  end  is  drilled  to  receive  the  point  of 
the  back  centre 
of  lathe,  which 
keeps  it  up  to  its 
cut.  Let  the  wheel 
to  be  bored  be 
chucked,  and  after 
being  drilled  (if 
required)  turn  out 
a  recess  the  exact 
diameter  of  the 
tool,  thus  :  ab  is  the  recess  ;  de^  top  of  rest ;  ^,  spanner  of 
back  centre.  Then  lay  the  tool  in  the  recess,  flat  side  up, 
place  a  spanner  on  the  shank,  which  is  squared,  and  let  span- 
ner lie  on  the  rest  so  as  to  prevent  the  tool  from  turning, 
screw  up  back  centre,  and  work  away.  Holtzapffel  keeps 
the  standard  tools  required. 


32 


MISCELLANEOUS  TOOLS, 


Sprinkling  Book  Edges.—  Procure  for  'red  edges  a  penny- 
worth of  Spanish  brown,  and  for  brown  edges  a  pennyworth  of 
burnt  umber,  and  take  sufficient  paste  to  mix  a  quantity  of 
either  colour  on  a  stone  slab,  adding,  when  well  mixed,  a  few 
drops  of  sweet  oil ;  then  put  the  mixture  into  an  earthenware 
jar,  and  add  some  water  to  it.  Before  using  it  stir  it  well  with 
an  iron-bound  brush,  then  twirl  the  brush  well  round  in  the  jar, 
and  strike  it  against  a  wooden  rod,  held  in  the  left  hand,  till  it 
throws  fine  spots  on  a  piece  of  paper  ;  then  proceed  in  the 
same  way  to  sprinkle  the  book  edges,  taking  care  to  wipe  the 
wooden  rod  occasionally. 

Home-made  Drill. — A  simple  drill  for  small  objects  can  be 
made,  as  shown  below,  for  about  six- 
pence. In  fig.  I,  AC  is  a  shaft  of 
common  deal,  thick  where  the  fly- 
wheel is  placed  and  tapering  towards 
each  end  ;  HE  is  the  flywheel,  also 
made  of  deal  and  weighted  with  lead  ; 
KL  is  the  wood  ;  and  HF,  HE,  two 
rings  of  lead  :  instead  of  rings  a  piece  ^ 
of  pipe    flattened  might  be  nailed  on 

ZF, 
of 


Fig.  2,  HZ, 


cross-bar  to   Y.     Pressure 
and  relaxed  to  the  bar. 


the  circumference. 

shows    the    breadth    of  the    rings 

lead ;    S  is  the  hole  where  the  shaft 

is  fixed.      Figs,    i    and   3,    NO   is  a 

cross-bar  working  on    the    shaft ;    S= 

is  the  hole  where  the  shaft  passes — 

this  must  be  loose  ;   N  and  O,  where 

the    twine    is    fixed  ;     PC  is    a   wire 

wrapping  to    hold  the    bit    (a    small 

bradawl)     firmly. 

The    working     is 

very  simple.    The 

twine    NX,    XO, 

must  be  fixed  at 

X,      and     wound 

round  the  shaft  a 

few  times,  which 

raises  the  arm  or 

must   then  be  alternately  applied 


Fig3. 


INSTRUMENTS,  AND  PROCESSES. 


Grinding  and  Polishing  Pebbles. — Pebbles  are  ground 
with  a  lead  wheel  and  emery,  the  emery  to  be  mixed  with 
water  to  a  paste  and  applied  with  a  small  brush  ;  after  they 
are  sufficiently  ground,  the  next  process  is  smoothing.  Work 
the  emery  on  the  wheel,  it  will  soon  sm.ooth  ;  if  the  wheel 
should  get  dry  or  blue,  take  a  little  more  emery  and  another 
stone,  and  smooth  it  on  the  wheel  and  then  finish  off  scratches. 
Now  for  polishing.  Be  sure  and  wash  all  the  emery  off  before 
commencing  this  step.  Polishing  is  done  on  a  block-tin  wheel 
with  rotten-stone.  All  the  wheels  run  horizontal,  and  are 
cast  about  8  in.  in  diameter 
and  turned  true. 

To  Cut  Brooch  Stones. — If 
the  pebbles  are  round  they 
must  be  slit.  This  is  done 
with  diamond-dust,  applied 
to  the  edge  of  a  tin  wheel 
with  the  finger,  and  then  oil 
is  kept  on  with  a  feather  as 
long  as  you  cut  ;  after  that, 
the  stones  are  blocked  to 
shape  with  a  pair  of  soft  iron 
nippers  6  in.  in  size,  and 
then  stuck  on  a  stick  and  cut 
into  shape  and  finished. 

Vertical  Drilling  -  Ma- 
chine.— This  small  machine 
can  be  fixed  upon  the  bed  of 
a  lathe,  and  worked  by  a 
small  pulley  on  the  flywheel 
shaft.  A,  the  bed ;  CC,  a 
wrought  -  iron  pillar  support- 
ing the  brackets  BB  ;  EEE, 
screws  for  holding  the  brackets  ; 
D,  hand  wheel  for  raising  and 
lowering  the  drill ;  F,  bolt  to 
the  end  of  the  pillar  C  for  holding  it  down  to  the  bed  of  a 
lathe. 

Another  design  is  shown  in  annexed  diagram. 

C 


31 


MIS  CELL  A  NEO  US  TO  OLS, 


work  ;  L,  blocks  to  keep  pulley  in  position. 


A  is  a  stand  of 
hardwood  with  up- 
right and  cross  piece 
at  top  firmly  fixed  ; 
B,  nuts  to  screw  the 
whole  to  bench  ;  C, 
flywheel ;  D,  crank 
for  treadle,  or  may 
be  shifted  towards 
the  outside  of  fly- 
wheel, and  act  as  a 
handle ;  E,  pulleys  ; 
F,  lead  weights  mov- 
ing nearer  centre  if 
required  ;  G,  pivot 
upon  which  extra 
weights  may  be 
placed  ;  H,  pulley; 
I,  piece  screwed  on 
to  work  in  slot  in 
pulley  ;  K,  dovetail, 
which  may  be  re- 
moved and  plate  M 
substituted,in  which 
the  squares  move 
towards  the  centre, 
and  thus  clamp  the 


INSTRUMENTS,  AND  PROCESSES. 


35 


Another  simple  machine  is  made  as  in  above  engraving. 
can  be  made  of  any  size  to  fix  on  the  table  conveniently. 
Drilling-machines  for  stoves,  &c.,  can  be  made  thus  : — 

Fig.  2.  :_  Fig.  I. 


It 


Fig.  I  shows  the  tool  applied  to  a  work-bench  j  fig.  2  as  apphed 
to  a  wall. 

Centre  Bit  for  Cutting  Leather  Washers. — A  is  a  piece 
of  iron  3  J  in.  long  by  J  in.  square,  tapered  at  the  end  to  fit  into 
a  common  joiner  brace.  The  bit  Ci  is  to  be  filed  out  with  a 
small  round  file  for  the  catch  in  the  brace  to  fit  it.  AA  is  a 
piece  of  iron   i  in.  thick,  i  in.  broad,  i  in.  long,  with  a  slot 


36 


MISCELLANEOUS  TOOLS, 


f  in.  square  through  it. 
same  as  that  of  a  lathe. 


B  is  the  slot,  D  is  the  centre,  the 
CC  is  the  shde,  f  in.  square,  to  fit  in 
the  slot.  HH  is  a 
square  piece  of  iron 
I  in.  long,  ^  in. 
broad,  i  in.  thick, 
with  a  slot  \  in. 
square  through  it. 
FF  is  the  cutter  that 
fastens  in  the  head 
HH.  G  is  a  thumb- 
screw that  fastens 
the  cutter  in  the 
head.  HH,  the 
cutter,  must  be  the 
same  shape  as  a 
Ci  in  the  cutter  must 
can    fit  in  to  keep  the 


spear-point  penknife-blade.      The  bit 

be  filed  out  so  that  the  thumbscrew 

cutter  fast.       E  is  for  a  thumbscrew  to  hold  slide  from  moving 

when  used. 


Water-Wheel.- 

the  buckets  from 


—The  leverage  in  all  the  weight  of  water  in 
D  to  E  is  the  same  as  the  pressure  of  a  col- 
umn of  water  of  cor- 
responding    dimen- 
sions suspended  from 
D  to  F.   The  shorter 
column  CE  would  be 
also   equal    to    CF ; 
but  experience  proves 
it  to  be  advisable  to 
throw  all  the  force 
into    a    column     of 
water,  as  above,  with 
full    buckets,   rather 
than   to   expend  velocity  at   a  lower  range,   the  intermediate 
buckets  from  C  to  E  being  only  partially  filled.      This  reason- 
ing can  apply  only  to  a  properly-made  breast-wheel. 

Cotton  Waste  may  be  thoroughly  cleansed  from  oil  and 
grease  in  the  following  way  :  It  is  put  into  an  iron  furnace 
(heated  with  steam  from  a  pipe  led  into  it),  together  with  a 


INSTRUMENTS,  AND  PROCESSES. 


37 


little  black-soap  and  soda, 
the  rushing  in  of  the  steam  keeps  the  waste  continually  moving, 
thus  freeing  it  of  its  impurities.  After  boiling  for  about  two 
hours,  it  is  taken  out  and  laid  on  a  boiler  or  warm  place  till  dry. 


To  Make  the  Ram  of  a  Hydraulic  Press  Water-tight. — 

The  ram  A  is  surrounded  by  a  collar  of  leather  D  ;  the  leather 
is  formed  as  shown  in  fig.  3,  being  turned  up  to  form  a  double 
cup,  so  that  it  resembles  the  cuff  of  a  coat-sleeve.  When  in 
its  place,  it  is  kept  distended  by  the  copper  ring  E  entering 
the  circular  channel  or  fold  of  the  leather.  This  ring  has  a 
lodgment  in  a  recess  formed  within  the  cyhnder  B.  The 
leather  is  kept  down  by  a  brass  or  bell-metal  ring  C,  which 
is  received  into  a  recess  formed  round  within  the  cylinder  B, 
as  shown  in  fig.  i.  The  interior  aperture  of  this  ring  is 
adapted  to  receive  the  ram  A,  and  thus  the  leather  becomes 
confined  in  a  cell,  with  the  edge  of  the  interior  fold  applied 
to  the  ram  A,  whilst 
the  edge  of  the 
outer  fold  is  in  con- 
tact with  the  inte- 
rior surface  of  the 
cylinder  B.  In  this 
situation  the  pres- 
sure of  the  water 
acting  between  the 
folds  of  the  leather, 
forces  its  edges  into 
close  contact  with 
both,  and  makes  a 
tight  fitting  round 
the     cylinder     and 

ram ;  and  as  the  pressure  of  the  water  is  increased,  the  leather 
is  applied  more  closely,  so  as  to  prevent  leakage  under  any 
circumstances.  The  metal  ring  C  is  truly  turned  in  the  lathe, 
as  well  as  the  cavity  or  cell  formed  for  its  reception ;  then  to 
get  it  into  its  place,  it  is  divided  by  a  saw  into  five  segments, 
as  shown  in  fig.  2.  Three  of  the  lines  by  which  it  is  divided 
point  to  the  centre,  but  the  other  two  are  parallel  to  each  other, 
and  the  ring  is  put  into  its  place  (after  the  leather  and  copper 
rings  are  introduced)  by  putting  in  the  four  segments  sepa- 


38 


MISCELLANEOUS  TOOLS, 


rately,  and  the  one  with  parallel  sides  is  put  in  last.  The  ram  A 
is  then  put  down  in  its  place,  and  ready  for  action.  The  upper 
part  of  the  cylinder  above  the  ring  C  is  filled  with  tow  or  other 
soft  packing  impregnated  with  sweet  oil,  which  is  confined  by  a 
thin  plate  or  ring.  A,  piston  or  ram  ;  B,  cylinder  ;  C,  brass  ring; 
Ci,  segment  with  parallel  sides  ;  D,  leather  collar  ;  E,  copper 
ring ;  F,  oiled  tow.      The  same  letters  refer  to  all  the  figures. 

Air-Engine. — The  principle  on  which  this  engine  works  is 
as  follows  : — 

The  air  at  the  bot- 
tom of  A  is  heated, 
and  thus  expands 
past  the  piston  B, 
which  is  made  to 
clear  ^  of  an  inch, 
reaches  the  top,  where 
the  brickdust  cools 
it,  thus  causing  a 
vacuum  under  piston 
in  D,  which  draws  it 
down. 

A,  main  cylinder 
regenerator.  Dimen- 
sions, 1 1  in.  dia- 
meter, 5^  in.  long. 

Ai,  top  or  cold 
end  of  ditto. 

A2,  hot  end  of 
ditto. 

1 


B,  hollow  piston  working  in  A,  \\  in.  diameter,  3 J  in.  long. 

C,  air-tube,  connecting  A  with  D. 

D,  working  cyHnder,  i  in.  diameter,  19-16  in.  long. 

E,  spirit-lamp  or  gas-jet. 

F,  casing  round  top  of  A,  containing  brickdust  to  keep 
down  heat. 

A,  length  of  stroke  =  i  J  in. 
D,  length  of  stroke  =  \\'m. 

Syphon,  the  Principle  of.— Let  a  bent  tube  ABC  have  its 
shorter  leg  AB  immersed  in  any  liquid — say  water — having 
been  previously   filled   with    the    same     liquid.       The    water 


INSTRUMENTS,  AND  PROCESSES. 


39 


will  be  maintained  up  to  the  level  D  by  the  force  of  the 
water  in  the  vessel,  and  may  therefore  be  left  out  of  con- 
sideration. 

The  forces  tending  to 
move  the  water  in  the 
direction  DBEC  will  be 
the  pressure  of  the  atmos- 
phere transmitted  through 
the  water  in  the  vessel, 
and  the  weight  of  water 
in  the  portion  BC.  The 
forces  tending  to  move 
the  water  in  the  opposite 
direction  will  be  the  pres- 
sure of  the  atmosphere 
acting  at  the  orifice  C,  and 
weight  of  water  in  the 
portion  BD. 

The    pressures    of    the 
atmosphere   being  equal  will  neutralise  each  other, 
will   be  a  tendency  of  the  water  to   move  towards 
portion  to  the  excess  of  BC  over  BD. 

A  syphon  will  conduct  water  from  a  high  to  a  lower  level. 
It  is  a  fundamental  law  in  hydrostatics,  that  the  pressure  of 
a  liquid  upon  any  point  is  in  direct  proportion  to  the  depth  of 
that  point  below  the  surface. 


and  there 
C,  in  pro- 


Air-Pumps.— 

It   has   not,     so 


I. 
far 


The   following   is 
as  we  are  aware. 


a 
been 


tried. 


an--pump. 
To  work 


it,  press  the  india- 
rubber  dome,  and 
let  it  return  until 
the  air  is  exhausted. 
A,  mahogany 
stand  covered  with 
a  brass  plate;  B,  re- 
ceiver; C,  india-rub- 
ber dome  to  act  as 
pump  ;  D,  wooden 
pad  to  protect  dome  from  the  spring  ;  E,  steel  spring  to  keep 
dome    stretched    out ;    F,    brass   cyHnder  on  which   dome  is 


..^ 


^ 


40 


MISCELLANEOUS  TOOLS, 


FICI, 


fastened ;  G,  valve  to  prevent  return  of  air  into  receiver ;  H, 
outlet  valve,  protected  by  brass  cage  ;  I,  screw  to  let  air  into 
dome  ;   J,  outlet  air  passage  ;    K,  exhaust  passage. 

2.  The  following  plan  will,  it  is  asserted,  answer  well  for 
small  experiments  : — 

If  applied  to  exhaust  the  air  from  a  large  receiver  it  should 
be  applied  only  as  a  finishing  pump,  as  the  action  is  slow 
compared  with  many  double-actioned  air-pumps. 

AA,  cylinder  of  brass  ;  B,  piston,  which  should 
have  a  thread  all  the  way  down  ;  CCCC,  plates 
of  brass,  with  DDD  layers  of  vulcanised  india- 
rubber  (i  inch  in  the  whole)  between,  which 
are  kept  firmly  in  place  by  means  of  the  screws 
EE.  F  shows  the  situation  of  the  tap,  the  work- 
ing of  which  is  shown  in  fig.  2.  The  tap,  as 
there  represented,  should  work  right  into  the 
cylinder,  but  not  to  interfere  with  the  action  of 
the  piston.  G  is  a  brass  plate,  and  should  be 
ground  down  so  as  to  fit  perfectly  air-tight 
to  the  end  of  the  cylinder  and  piston  ;  H  is  a 
brass  cap  for  the  purpose  of  holding  on  the 
brass  plate  G  during  the  first  move  of  the 
piston. 

The  pump  should  be  worked  in  the  following 
manner  : — 

Screw  down  firmly,  by  means  of  the  nuts 
EE,  the  brass  plates  and  layers  of  vulcanised 
india-rubber  marked  C  and  D  in  the  diagram, 
to  the  bottom  of  the  piston  ;  then,  having  forced 
down  the  piston  to  the  bottom  of  the  cylinder,  . 
which  is  made  to  fit  level  to  the  end  of  the 
cylinder,  put  the  brass  plate  G,  with  a  little 
grease  rubbed  on  the  inside  face  of  it,  against  it — 
this  will  be  kept  in  its  place  by  the  cap  H  ;  then 
the  tap  being  turned  so  as  to  open  a  communica- 
tion with  the  receiver,  draw  up  the  piston  the 
full  length  of  the  cylinder — this  will  remove  a 
cylinderful  of  air  from  the  receiver  ;  then  eject 
this  quantity  of  air  by  cutting  off  the  communication  with  the 
receiver  and  pushing  down  the  piston.  Repeat  this  process 
till    a   perfect    vacuum    is  formed.     [The  above  is  interesting 


FIG  s 


INSTRUMENTS,  AND  PROCESSES. 


41 


as    a    suggestion, 
tested.] 


We  believe  it  has  never  been  practically 


All  the  pump-plungers  are 


Capstan  Pumps  for  Hydraulic  Presses. — The  arrange- 
ment of  pumps  for 
working  hydraulic  [^i 
presses  shown  by 
our  engravings  has 
been  invented  and 
patented  by  Messrs 
Peel  of  Manchester. 
The  pumps  are 
placed  in  a  hori- 
zontal position,  with 
their  axes  radial  to 
the  circle  formed  by 
the  lid  of  the  cylin- 
drical water-cistern,  ^"^"^ 
to  which  all  the  pumps  are  fixed, 
connected  to  an  ec- 
centric disc,  keyed 
on  to  the  vertical 
capstan  shaft,  which 
in  this  manner  forms 
the  crank  for  all  of 
them,  since  at  every 
revolution  of  the  ec- 
centric each  pump 
completes  a  full 
double  stroke.  The 
pumps  enter  the 
corresponding 
phases  of  their 
movements  in  rota- 
tion, and  divide  the 
power  very  regu- 
larly all  over  the 
circle.  The  power  is  applied  direct  to  the  levers  of  the  capstan, 
the  form  of  which,  as  shown  in  the  drawing,  is  intended 
for  being  worked  by  men.  An  arrangement  is  provided 
for   throwing    the    greater    number  of  pumps  out  of    action 


42  MISCELLANEOUS  TOOLS, 

when  the  pressure  increases  beyond  a  certain  point,  so 
that  the  ultimate  compression  given  to  the  bale  can  be  increased 
by  these  means. 


Cork  Springs. — In  a  report  upon  new  mechanical  appli- 
cations the  secretary  of  the  Franklin  Institute  called  attention 
to  the  use  of  cork  in  place  of  india-rubber  as  a  support  for 
freight  cars  and  like  heavy  vehicles.  One  would  not  be  led  by 
any  means  to  predict  the  efficiency  of  cork  in  this  connection 
from  ordinary  impressions  of  its  properties.  The  cork  used  for 
these  springs  is  of  the  commonest  description,  harsh,  hard,  and 
full  of  fissures.  It  is  cut  into  discs  of  about  8  inches 
diameter,  each  pierced  with  a  central  hole.  Previous,  how- 
ever, to  cutting  it,  it  is  soaked  in  a  mixture  of  molasses  and 
water,  which  gives  it  some  softness  and  renders  it  permanently 
moist.  A  number  of  these  cork  discs  are  placed  in  a  cylin- 
drical cast-iron  box,  a  flat  iron  lid  or  disc  is  placed  over  them, 
and  by  hydraulic  pressure  is  forced  down  so  as  to  reduce 
the  thickness  to  one-half.  A  bolt  is  then  run  through  box, 
corks,  and  cover  at  the  centre,  and  a  nut  being  screwed  on  this, 
holds  all  in  place,  when  the  press  is  relieved,  and  the  box  of 
compressed  cork  disc  or  cork  spring  is  ready  for  use.  One 
of  these  springs,  placed  in  a  testing  machine  under  a  weight  of 


INSTRUMENTS,  AND  PROCESSES. 


43 


20,000  lb.,  shows  an  elasticity  suggestive  of  compressed  air  in 
a  condensing  pump.  One  would  expect,  from  the  appearance 
of  the  material,  that  under  heavy  pressure  it  would  be  pulverised 
or  split  into  shreds,  especially  if  this  pressure  was  assisted  by 
violent  shocks  ;  but,  in  fact,  no  such  action  takes  place.  A 
pressure  which  destroys  india  rubber,  causing  it  to  split  up  and 
lose  its  elasticity,  leaves  the  cork  unimpaired  ;  and  with  the 
machinery  in  use,  it  has  even  been  impossible,  with  any 
pressure  attainable,  to  injure  the  cork,  even  when  areas  of  but 
I  inch  was  acted  upon.  In  connection  with  this  subject,  the 
president,  Mr  William  Sellers,  remarked,  at  the  conclusion  of 
the  secretary's  report,  that  he  had  for  some  five  years  employed 
a  forging-machine  in  which  a  spring  of  the  form  and  material 
above  described  was  used,  and  subjected  to  continual  and 
violent  shocks,  and  that  its  performance  had  been  most 
thoroughly  satisfactory,  with  no  signs  of  deterioration. 


Camera  Obscura  for  Drawing  Objects. — The  following 
sketch  will  be  useful  to  amateurs  wishing  to  construct  a  camera 
obscura.  The  best  form  of  lens  is  a  Meniseus  (the  focus  for 
sketch  16  in.)  with  its 
convex  side  to  the  mir- 
ror, the  diameter  2\ 
in.,  the  mirror  4  in.  by 
3  in.  K  is  a  hole  to  see 
the  image.  One  of  the 
sides  is  made  to  open,  for 
the  hand  to  draw  the  ob- 
ject. The  height  of  the 
camera  is  19  in.  ;  the 
lens  to  be  15  in.  from 
the  bottom  ;  the  mirror 
to  be  as  close  to  the 
lens  as  possible,  at  an 
angle  of  45°.  The  mir- 
ror and  lens  should  be  ■  b  oTiy 
made  in  a  square  box  to  fit  in  the  top,  so  as  to  allow  the  sides 
abc  to  fall  in,  and  d  to  form  a  lid. 


Pump   for   Deep  Wells. — A   model   pump,  made   by   an 
ordinary  tinworker,  is  thus  described  : — 


44 


MISCELLANEOUS  TOOLS, 


The  barrel  was  about  the  size  of  a  pint  mug,  the  pipe  was 
about  3  ft.  long.  Filled  with  water, 
it  was  found  that  the  water  in  the 
barrel  balanced  the  water  in  the  pipe, 
and  remained  there  by  keeping  the 
lower  end  of  the  sucking  pipe  under 
water  ;  consequently,  a  .  pump  fixed  on 
the  short  pipe  C  would  work  with  as 
much  ease  as  though  the  water  rose  to 
the  top  of  the  well.  A  is  an  opening 
to  fill  it  with,  and  while  filling,  the 
short  pipe  C  must  be  stopped  when 
full.  Secure  the  opening  at  A,  making 
it  air-tight. 

This  pump  will  require  a  valve  to  act 
with  the  bucket.  For  convenience  the 
barrel  B  may  be  put  above,  below,  or 
half-way  with  the  surface  of  the  ground. 

The  opening  at  the  top  A  may  be 
omitted  in  a  miniature  model,  as  it 
will  only  be  required  for  convenience 
in  a  large  domestic  concern. 

Pump    for    Tube    Wells. — During 
the   Abyssinian    War    the  Government 
supplied   various    kinds    of  pumps,    of 
which  the  following  was  the    best    ex- 
ample.    The  whole  apparatus    is  very 
simple   and  ingenious,  being  one  of  the 
numerous  American  inventions  designed 
for  the  saving  of  labour,  more  especially 
in  farming  and  mining  districts. 
A  well  on  this  new  principle  may  be  sunk  in  from  one  to 
three  hours.      The  tube   of  the  well   is   simply  an  iron  gas  or 
steam  pipe  i^  in.  in  internal  diameter. 

The  lower  end  of  the  tube  AB  in  the  accompanying  diagram 
is  furnished  with  a  solid  steel  or  case-hardened  iron  spike  B 
of  the  shape  of  a  four-sided  pyramid.  The  lowest  end  of  the 
pipe  itself  is  pierced  by  numerous  small  holes  at  N.  After  the 
pipe  has  been  driven  into  the  ground,  a  small  pump  is  screwed 
into  the  top ;   the  water,  if  present  in  the  place,  finds  its  way 


LOWER  VALVS 


IiVSl'RUAIENTS,  AND  PROCESSES. 


45 


through  the  holes  at  N,  and  may  be  pumped  up  to  a  height 
not  much  exceeding  28  ft.,  which  is  usually  all  that  is  neces- 
sary. 

Not  the  least  ingenious  aspect 
of  this  useful  little  invention  is 
the  method  of  driving  the  pipe 
into  the  ground  with  the  smallest 
expenditure  of  time,  labour,  and 
materials. 

The  movable  clamp  F  is 
tightly  screwed  to  the  outside  of 
the  tube,  above  the  level  of  the 
ground  HK.  Near  the  top  of 
the  tube,  some  distance  above 
A,  a  similar  clamp  is  fixed, 
which  upper  clamp  carries  two 
pulley-wheels  for  ropes.  The 
same  ropes  also  pass  round  the 
pulley-wheel  DE  of  the  monkey 
C.  By  means  of  the  ropes  a 
couple  of  men  can  easily  pull  the 
monkey  C  up  the  pipe,  and 
suddenly  let  it  fall  upon  the 
edges  of  the  clamp  F  ;  and  the 
force  of  each  blow  of  course 
drives  the  pipe  deeper  into  the 
ground.  By  successive  blows 
the  clamp  F  at  last  reaches  the 
level  of  the  ground  HK,  when 
it  is  unscrewed  and  refixed 
higher  up  the  pipe.  The  upper 
clamp  may  be  shifted  in  a 
similar  manner,  and  in  this  way 
the  pipe  AB  can  be  driven,  if 
necessary,  as  deeply  into  the 
ground  as  a  pump  can  raise 
water. 

The  advantages  claimed  for  Norton's  Patent  American  Tube 
Well,  as  it  is  called,  are — 

I.  That  it  costs  only  a  tithe  of  a  bored  or  dug  well,  and 
saves  water-rates,  because  by  the  11  and  12  Vict.   cap.  63,  it 


46 


MISCELLANEOUS  TOOLS, 


is  enacted  that  no  water-rates  can  be  levied  wliere  there  are 
pumps  giving  a  proper  supply  of  water. 

2.  That  the  water  is  purer  than  usual,  because  of  freedom 
from  the  upper  surface  drainage. 

3.  That  by  this  method  wells  may  be  easily  made  in  loose 
soil,  atid  the  strata  below  may  be  pierced  should  there  be  no 
water  at  the  bottom  of  the  loose  soil  aforesaid, 

A  plan  somewhat  similar  to  this  has  long  been  in  use  to  raise 
salt  from  its  subterranean  beds.  Sir  Robert  Kane,  M.D.,  in 
his  book  on  ^'  Chemistry,"  says  :  "  Owing  to  the  admixture  of 
earthy  matters,  the  rock-salt,  as  quarried,  is  generally  brownish 
coloured,  and  hence  requires  to  be  dissolved  in  water  and 
crystallised  for  use.  The  expense  of  extracting  the  salt  may 
be  in  many  cases  lessened  by  simply  boring  down  to  the  bed 
with  a  pipe  a  few  inches  in  diameter,  and  letting  thereby 
water  run  in  upon  the  salt ;  a  strong  solution  of  salt  is  thus 
produced,  which  is  pumped  up  and  evaporated.  The  expense 
of  sinking  a  shaft  and  quarrying  out  the  solid  salt  is  thus 
avoided." 


Sack-Holder. — The  diagrams  below  illustrate  a  simple  and 
Fic  I  J  Fica 


useful  invention  for  sack-holding,  inasmuch  as  it  is  the  saving 
of  a  vast  amount  of  labour  and  material.      It  possesses  several 


INSTRUMENTS,  AND  PROCESSES. 


47 


decided  advantages,  combining  strength  with  simple  construc- 
tion and  direct  action.  The  height  can 
be  regulated  as  required  by  opening  or 
closing  the  legs  ee,  being  kept  in  the 
required  position  by  the  perforated  plate  d, 
which  is  fastened  at  /,  passed  through  an 
opening  in  _/,  and  is  held  by  the  iron  pin  g. 

After  adjusting  the  holder  to  the  proper 
height,  fold  the  back  part  of  the  mouth 
of  the  sack  outwards,  place  it  over  the 
clamping-bar  b,  draw  the  spring  arms  cc 
forwav^ail,  and  place  the  hooks  over  ee ;  the 
sack  will  then  be  firmly  held  between  the 
bars  ab  (fig.  2).  In  this  position  it 
can  be    conveniently 


SSSi 
g 

I 
J 

III  ! 


filled  by  one  man, 
thus  saving  the  labour 
of  a  second  to  hold 
the  sack.  When  the 
sack  is  filled  it  is  set 
free  instantly  by  un- 
fastening the  springs. 
By  a  simple  modi- 
fication of  the  above 
the  "holder  "  may  be 
adjusted  on  wheels, 
thus  combining  with 
it  sack-cart  (-fig.  3). 
It  can  also  be  fixed  on  beams  or  walls  (figs.  4  and  5). 

Diamonds,  to  Polish. — The  plan  in  use  at  all  the  large  dia- 
mond-cutters^ is  simply  a  circular  cast-iron  disc  of  good  metal, 
with  a  vertical  spindle  running  through  its  centre,  balanced  and 
turned  and  faced  true  in  a  lathe.  The  disc  revolves  at  about 
1000  revolutions  per  minute.  With  a  little  diamond-dust  and 
oil  the  stone  is  set  in  a  small  brass  cup  filled  with  common  soft 
solder ;  it  is  then  screwed  up  in  the  clamps,  and  applied  to  the 
skive  till  the  facet  is  formed. 

To  Fasten  Driving  Straps. — Two  thin  metal  plates,  their 
inner  faces  roughened  like  those  of  a  vice,  and  held  together 
by  screws,  form  a  cheap,  strong,  and  convenient  fastening  for 


48 


MISCELLANEOUS  TOOLS, 


driving  straps.  If  the  strap  stretch,  the  screws  (which  pass 
between  the  ends  of-  and  not  through  the  strap)  have  only  to 
be  loosened,  the  ends  of  the  leather  cut  shorter  and  clammed 
anew. 


To  Draw  Radii  to  Inaccessible  Centres. — The  following 

instrument  will  be  of  use : 

A  is  the  blade  with  a  slot 
in  one  end  for  set  screw' 
C  to  work  in. 

BB  are  the  legs  \o  run 
against  cylinder,  i^^. 

DD  are  radius  bars  to 
keep  the  blade  central. 

Bookbinding  —  Mar- 
bling.— Use  the  follow- 
ing colours :  Scarlet  drop 
lake,  Chinese  blue,  indigo 
blue,  ultramarine,  orange 
lead,  Dutch  pink.  Chinese 
blue  can  only  be  used  by 
grinding  with  a  small 
piece  of  pipeclay,  and 
when  properly  ground, 
add  a  little  gum  arable 
dissolved  in  water.  Ul- 
tramarine blue,  with  a 
small  portion  of  indigo, 
makes  a  good  colour,  and 
is  less  troublesome  to 
manage,  but  does  not 
stand  so  well.  Green, 
indigo  and  Dutch  pink,  mixed  to  the  shade  required.  Red, 
use  scarlet  drop  lake.  All  the  above  colours  must  be  ground 
in  neat  gin,  no  water  to  be  used  either  in  grinding  or  after- 
wards. A  few  drops  of  ox  gall  must  be  put  in  each  colour  to 
make  it  spread  on  the  size.  Use  the  colours  about  the  thick- 
ness of  treacle. 

Size. — This    is    the  principal    ingredient  in  marbling,  and 
therefore  requires  much  attention.      Use  the  best  gum  drachan, 


INSTRUMENTS,  AND  PROCESSES. 


49 


which   should   be   white   and   clean  ;   soak  a  handful   in   soft 
water  for  twenty-four  hours,  beat  well  up  with  a  roller,  then  add 
water  until  about  the  thickness  of  cream  ;   pour  through  a  sieve 
into  your  trough,   let  it 
stand    to    clear,    add    a 
little     salt,     and    it     is 
ready  for  use.     For  non- 
pareil   marble    use    the 
same  size,  but  thinner  ; 
and    in     grinding     the 
colours,     add     a     little 
bees-wax     dissolved    in 
turps. 

Gas  -  Generator. — 

Procure  a  half-gallon 
jar  capable  of  standing 
a  good  pressure,  then 
turn  a  cap  to  fit  the 
neck  with  a  screw  in- 
side, as  N  ;  then  the 
headpiece  P,  with  a 
screw  at  S  to  fit  into  N, 
the  head  to  contain  a 
tap  moved  by  a  handle 
H,  when  the  water  will 
be  forced  through  the 
glass  tube  A,  which 
must  be  connected  with 
the  opening  O,  and  reach 
to  wdthin  |-  in.  of  the 
bottom   of   thejar.       To 

work  it,  fill  it  three  parts  full  of  water,  then  add  1  oz.  each 
of  carbonate  of  soda  and  citric  acid,  or  a  sufficient  quantity 
to  generate  gas  enough  to  force  the  water  up  through  the 
tube. 


Papier  Mache'. — The  substance  known  as  papier  machd  is 
extensively  employed  in  the  construction  of  tea-trays,  picture- 
frames,  &c.,  and  even  railway  carriages.  There  are  two  kinds — 
the  pasted  sheets  and  the  macerated.      The  latter,  which  is  the 


50 


MISCELLANEOUS  TOOLS, 


more  common,  is  made  of  paper  cuttings  boiled  in  water,  and 
beaten  in  a  mortar  till  they  are  reduced  into  a  kind  of  paste, 
and  then  boiled  with  a  solution  of  gum  or  size,  to  give  tenacity 
to  the  paste,  which  is  afterwards  formed  into  different  articles 
by  pressing  into  oiled  moulds  ;  when  dry  it  is  varnished  and 
pohshed.  The  black  varnish  for  papier  mache  toys  is 
thus  prepared  :  Some  colophony,  or  turpentine  boiled  down 
till  it  becomes  black  and  friable,  is  melted  into  a  glazed 
earthen  vessel,  and  thrice  as  much  amber  in  fine  powder 
sprinkled  in  by  degrees,  with  the  addition  of  a  little  spirit  or 
oil  of  turpentine  now  and  then  ;  when  the  amber  is  melted, 
sprinkle  in  the  same  quantity  of  sarcocolla,  continue  from  time 
to  time  to  stir  them  and  to  add  more  spirit  of  turpentine  till  the 
whole  becomes  fluid,  then  strain  out  the  clear  through  a  coarse 
hair  bag,  pressing  it  gently  between  hot  brands.  This  varnish 
mixed  with  ivory-black,  in  fine  powder,  is  applied  in  a  hot  room 
on  the  dried  paper  paste,  which  is  then  set  in  a  gently-heated 
oven,  next  day  in  a  hotter  oven,  and  the  third  day  in  a  very 
hot  one,  and  let  stand  each  time  till  the  oven  grows  cold. 
The  paste  then  varnished  is  hard,  durable,  glossy,  and  bears 
liquors  hot  or  cold. 

Wheeled  Skates. — The   following   sketch   is   sufficient  to 

allow  any  clever  mechanic  to 
make  a  pair  of  wheeled  skates 
that  can  be  used  both  in  and 
out  of  doors,  on  any  level 
ground.  They  are  fastened 
on  the  feet  with  a  strap  from 
heel  to  instep,  and  a  couple 
of  straps  across  the  toes.  A 
screw  passes  into  the  heel,  at 
the  back  instead  of  the  bottom, 
as  in  the  ordinary  skate.  The 
skate  itself  is  formed  of  iron, 
slightly  curved  to  fit  the  foot, 
and  rolls  upon  four  Httle 
wooden  wheels,  with  indiarubber  tires. 


Omnibus  Register. — Various  plans  have  been  from  time  to 
time  suggested  for  registering  the  number  of  passengers  carried 


INSTRUMENTS,  AND  PROCESSES. 


51 


in  and  upon  an  omnibus  during  the  day.  The  present  plan 
of  expecting  the  conductors  to  mark  down  each  "  fare  "  upon 
a  card  is  confessedly  incomplete,  and  the  more  simple  one  of 


O       M 


o 


umnious  Passenger  Regutering  Alackine. 

giving  each  passenger  a  ticket  from  a  numbered  book  does  not 
seem  to  have  suggested  itself  to  the  omnibus  proprietors. 
The  following  apparatus  for  registering  the  number  of  passen- 


52 


MISCELLANEOUS  TOOLS, 


gers  conveyed  and  the  amount  of  money  taken  has  been  in- 
vented by  Mr  R.  H.  Thomas  of  Kidsgrove,  near  Birmingham, 
Fig.  I  of  the  diagrams  is  a  J-size  plan  of  the  machine  closed 
ready  for  use,  to  be  suspended  under  the  left  arm  by  the  two 
rings  00  to  a  shoulder  strap,  the  hollow  side  next  the  body, 
and  the  cover  C  towards  the  right  hand. 

Fig.  2  is  an  elevation  with  the  front  plate  L  and  the  bearing 
bar  M  removed  to  show  the  movement. 

A  is  a  thumbstand  on  a  sliding  rod  jointed  at  the  bottom 
end  to  a  ratchet  hook  B  and  a  spring  S  ;  C  is  a  cover  for 
protecting  the  stud  A  when  not  in  use,  but  is  turned  up  to  the 
dotted  lines  when  it  is  required  ;  D  is  a  detent  click  and 
hammer  ;  E  is  a  spring  to  force  it  down  in  the  ratchet  teeth, 
and  at  the  same  time  to  strike  the  bell  R  ;  F  is  a  plate  ratchet 
wheel  numbered  for  pence,  from  i  to  12  and  from  i  to  12, 
V  ith  a  pinion  on  its  arbour,  which  drives  the  shilling  plate  wheel 
G,  with  another  pinion  to  drive  the  pounds  wheel  H  ;    I  I  I  are 

three  indicators  point- 
ing to  the  numbers 
on  the  wheels  F,  G, 
and  H  ;  R  is  a  bell 
on  the  arbour  of  the 
wheel  H. 

Ratchet-wheels. 

• — RW,ratcheton  end 
of  wheel  nave,  both 
cast  together  ;  CC, 
a  collar  on  the  shaft 
end  which  works  in- 
side of  nave  \  C,  a 
movable  catch  kept 
in  its  place  by  the 
small  spring  S.  The 
collar  answers  for 
two  purposes — viz., 
to  keep  the  wheel  on  and  to  work  it  round.  D  is  a  set  screw  to 
fasten  a  tin  cap  on  end  of  nave  or  boss  of  the  wheel ;  SC  is  a 
set  screw  to  fasten  the  collar  on  the  shaft ;  WBC,  the  wheel 
boss  and  cap  fitted  on  over  the  ratchet.  The  ratchet  is  a  rim 
by  itself,  and  may  be  cast  at  rights  and  lefts. 


INSTRUMENTS,  AND  PROCESSES. 


FIC 


Cutting  out  Bowls. — An  inspection  of  fi^ 
that  after  the  first  groove 
is  cut,  a  very  long 
straight  hook  can  be 
placed  beside  the  centre 
block,  but  it  would  be 
impossible  to  place  it  for 
the  edge  to  cut.  But  in 
fig.  2,  a  small  tool, 
figure  I,  is  shown  in 
position,  and  it  can  be 
brought  to  touch,  cut 
the  block,  and  when 
gradually  advanced  till 
the  shank  of  the  tool 
touches  the  block,  will 
be  undercut  to  the 
dotted  line.  Then  you 
can  place  2  so  as  to 
begin  to  cut,  it  is  so 
placed  to  commence 
where  the  other  left 
off;  by  the  time  this 
has  been  advanced  the 
block  will  be  undercut 
to  the  second  dotted 
line.  Insert  a  longer 
one  in  the  same  way 
till  the  block  falls  out. 
With  curved  hook  tools 
wooden  bowls  are  thus 
cut  out  one  from  inside 
another,  so  as  to  have  no  waste. 


I   will  show 


Ivory  BleacMng. — Should  antique  works  in  ivory  become 
discoloured,  their  original  whiteness  may  be  recovered  by 
exposing  them  under  a  glass  shade  to  the  action  of  the  sun's 
rays.  If  a  piece  of  sculpture  is  disfigured  with  cracks,  although 
these  defects  cannot  be  removed,  they  may  be  rendered  much 
less  apparent  by  brushing  them  over  with  soap-and-water.  The 
process  of  bleaching  will  be  much  accelerated  if  before  exposing 


54  MISCELLANEOUS  TOOLS, 

to  the  sun,  the  articles  are  brushed  over  with  calcined  diluted 
pumice-stone. 

Ivory  Cleaning.  —  Rub  it  with  finely-powdered  pumice- 
stone  and  water,  expose  to  the  sun  whilst  moist  under  a  glass 
shade,  and  repeat  until  the  whiteness  is  restored;  or  immerse 
for  a  short  time  in  water  slightly  mixed  with  sulphuric  acid, 
chloride  of  lime,  or  chlorine,  or  it  may  be  exposed  in  the  moist 
state  to  the  fumes  of  burning  sulphur,  largely  diluted  with  air. 
Ink-stains  may  be  removed  by  repeatedly  using  a  solution  of 
quadrozalate  of  potassa  in  water. 

Ivory,  to  Soften. — Dr  Lankester  recommends  phosphoric 
acid,  of  the  usual  specific  gravity,  which  renders  ivory  soft  and 
nearly  plastic.  When  washed,  with  water,  pressed,  and  dried, 
the-  ivory  regains  its  former  consistency,  and  even  its  micro- 
scopic structure  is  not  affected  by  the  process. 

Dyes  for  Ivory. — Billiard-balls  and  other  articles  in  ivory 
are  often  dyed.  A  good  red  dye  may  be  given  by  first  imbuing 
the  ivory  in  a  solution  of  nitro- muriate  of  tin,  and  then  plung- 
ing it  in  a  bath  of  Brazil  wood  and  cochineal.  Lac  dye  may  be 
used  with  still  more  advantage  to  produce  a  scarlet  tint.  If 
the  scarlet  ivory  be  plunged  for  a  short  time  in  a  solution  of 
potash,  it  will  become  cherry  red.  To  dye  a  purple  the  ivory 
must  first  be  mordanted  for  a  short  time  in  the  above  solution 
of  tin,  and  then  immersed  in  a  logwood  bath.  This  gives  a 
violet  colour.  When  the  bath  becomes  exhausted  it  imparts 
a  lilac  tint.  Violet  ivory  is  changed  to  purple  by  steeping  it 
a  little  while  in  water  containing  a  few  drops  of  nitro-muriatic 
acid.  The  aniline  dyes  can  only  be  used  for  mauve  and 
magenta,  but  unfortunately  they  soon  fade.  To  dye  ivory  green 
it  must  first  be  dyed  blue  by  immersing  it  for  a  longer  or  shorter 
time,  according  to  the  depth  of  colour  required  in  a  dilute  solu- 
tion of  sulphate  of  indigo,  partly  saturated  with  potash.  After- 
wards dipping  the  blued  ivory  in  the  solution  of  nitro-muriate 
of  tin,  and  then  in  a  hot  decoction  of  fustic.  By  omitting  the 
indigo  bath  the  ivory  will  be  dyed  a  fine  yellow.  Ivory  takes 
the  dyes  much  better  previous  to  polishing.  Should  any  dark 
spots  appear,  they  may  be  cleared  up  by  rubbing  them  with 
chalk  ;  after  which  the  ivory  should  be  dyed  once  more  to 
produce  perfect  uniformity  of  shade.      On  taking  it  out  of  the 


INSTRUMENTS,  AND  PROCESSES. 


55 


boiling  hot  dye  bath,  it  cught  to  be  immediately  plunged  into  cold 
water  to  avoid  the  chr.nce  of  fissures  being  caused  by  the  heat. 

A  simple  way  of  dyeing  old  billiard-balls  is  to  procure  a  piece 
of  thin,  fine-faced  scarlet  cloth,  wrap  it  tightly  round  each  ball, 
being  very  careful  to  have  as  few  creases  in  it  as  possible,  and 
boil  in  water  till  the  colour  has  reached  the  required  depth. 
Rough-faced  cloth  will  give  the  balls  a  mottled  appearance. 

Another pla?i  is  to  take  2  ounces  of  verdigris  and  i  ounce 
of  sal-ammoniac,  grind  them  well  together,  pour  strong  white 
wine  vinegar  upon  them,  and  put  your  ivory  balls  in.  Let  them 
lie  covered  till  the  colour  has  penetrated. 

Saving  Life  on  the  Ice. — Below  is  a  diagram  of  a  proposed 
raft  to  be  used  in  rescuing  persons  from  drowning  consequent 
upon  the  breaking 
up  of  the  ice.  It 
is  constructed  upon 
the  well-known  plan 
of  the  toy  regiment 
of      soldiers.         It 

might  be  made  of  battens  5  ft.  long,  4  in.  by  2  in,, 
bolted  together,  having  a  few  friction  rollers  ;  and 
irons  turned  up  at  ends  similar  to  skates.  By 
means  of  the  two  ropes  it  could  be  worked  from 
the  bank,  and  got  into  any  desired  position  with 
great  facility.  Such  rafts  would  be  very  useful  to  cover  any 
weak  place  on  the  ice,  and  one  or  two  extended  would  be 
effectual  in  keeping  it  clear  of  skaters.  The  whole  would 
occupy  about  5  ft.  square,  and  when  extended  would  form  a 
raft  50  ft.  long  and  4  ft.  wide. 

Vellum  Cleaning. — Muriate  of  tin,  oxalic  acid,  binoxalate 
of  potash,  of  each  J  ounce ;  powdered  pumice  -  stone  and 
cream  of  tartar,  2  ounces  of  each,  and  water  2  pints.  Put 
all  together  and  allow  to  remain  till  the  oxalic  acid  and  bin- 
oxalate of  potash  are  dissolved.  Shake  well  up  before  using, 
and  rub  well  the  bindings  with  it,  by  means  of  a  sponge  or 
piece  of  flannel,  till  clean.  The  bindings  should  turn  out 
nearly  white.  Ink-stains  will  mostly  be  taken  out.  It  will  be 
well  not  to  try  to  do  too  much  at  once,  as  more  good  may  be 
done  by  applying  a  second  time,  in  a  day  or  two,  after  the 
books  have  got  dry. 


S6 


MISCELLANEOUS  TOOLS, 


Parchment  Cleaning. — Strain  the  parchment  tight  with  the 
jElnger  and  thumb  over  a  ruler,  and  "  shave"  it  out  (the  very- 
same  action  being  used  as  when  shaving  the  face)  with  a  very- 
thin  sharp  knife.  The  two  principal  difficulties  in  this  are,  not 
bringing  the  pieces  clear  off,  and  thereby  leaving  jagged  ends  ; 
and  bringing  them  too  clear  off — i,e. ,  making  holes.  When 
he  has  mastered  this  the  amateur  will  be  able  to  cut  out  a  line 
or  two,  if  he  hkes,  and  it  will  be  scarcely  visible  unless  held  up 
to  the  light. 

Tortoiseshell,  to  PoKsh. — Handles  and  similar  work  are 
first  sawn  into  shape,  then  filed  and  scraped  with  a  joiner's 
scraper  ;  afterwards  polished  on  a  buff  wheel,  first  with  cal- 
cined Trent  sand,  and  finished  on  another  wheel  with  oil  and 
rottenstone.  Flat  works  are  treated  in  a  similar  way  with  flat 
pods.  Turnery  works  are  smoothed  with  fine  glass  or  emery- 
paper,  and  finished  with  rottenstone  and  oil,  Horn  is  treated 
in  the  same  way,  but  the  sand  need  not  be  calcined. 

Cutting  Hinges.  —  Amateurs  will  find  the  following  plans 
useful  for  cutting  the  concave  parts  of  hinges  :  The  holes  aaa^ 
fig.  I,  are  first  drilled  to  admit  the  steel  rod,  fig.  2,  which  has 

one  end  squared  to 
enable  it  to  be  turned  by 
a  hand-vice.  On  this 
rod  fits  the  cutter,  fig. 
3,  which  is  a  cylindrical 
piece  of  hard  steel  bored 
to  fit  the  rod,  and  cut 
with  teeth  on  the  outer 
cylindrical  part  and 
on  one  fiat  surface  ;  a 
pin  is  inserted  through 
both  the  cutter  and  bar, 
so  that  the  two  may  be 
united  after  they  have 
been  placed  within  the 
joint  to  be  worked.  A 
recess  must  first  be  cut  to  admit  the  cutter,  and  then  the  hollow 
parts  of  fig.  i  are  cut  throughout  their  length  with  the  cutter, 
which  afterwards  serves  to  flatten  the  faces  of  the  knuckles  in 
exact  parallelism  throughout  and  at  right  angles  to  the  central 


INSTRUMENTS,  AND  PROCESSES. 


57 


hole.  For  cutting  the  knuckles  and  tenons  for  the  small  joints 
of  mathematical  instruments,  &c.,  such  as  fig.  4,  the  work  is 
usually  supported  on  a  small  iron  platform,  the  surface  of 
which  is  horizontal,  with 


FIG. 5. 


a    notch  to    receive    the 

saw    B   (worked  by  the 

lathe)  and  a  cylindrical 

stem     C    to    adapt   the 

platform  to  the  bed-piece 

of  the  common  rest.  This 

platform  is  fixed  a  little 

below  the  axis,  in  order 

to    place    the    knuckles 

exactly     central    to    the 

saw,  so  as   to  make  the 

notches  equally  deep  on 

both    sides,    and    if   the 

surface  of  the   platform 

is  parallel  with  the  axis  'Hv-N' 

of  the  spindle,  the  notch  is  sure  to  be  square  with  the  side  of 

the  work.      For  fig.   4,  E,  two  saws  are  used  upon  the  same 

spindle  to    ensure  the  parallehsm  of  the  sides  of    the  middle 

piece  or  tenon.      Fig.  6  will  also   answer   the    same  purpose 

without   a  lathe,   by  passing  a  pin  through  the  centre  hole  and 

working  it  backwards  and  forwards  in  the  hinge  to  be  finished. 


Kaleidoscope. — Below  is  a  suggested  improvement  upon  the 
old  style  of  kaleidoscope.  It  claims  to  be  better  inasmuch  as 
the  body  of  it  does  not  require  turning.  The  objects  change 
by  turning  the  small 
shaft  that  drives  the 
wheels.  The  large 
one  is  only  a  toothed 
rim,  into  which  is  fixed 
a  tin  case  with  a  glass 
at  each  end,  between 
which  are  fragments 
of  coloured  glass.  The 
whole  is  fitted  in  a  box  with  ground  glass  at  one  end  and  a 
convex  lens  on  the  other. 

The  simplest  form  of  kaleidoscope  consists  of  a  cylinder  of 


58 


MISCELLANEOUS  TOOLS, 


tin,  in  which  two  plain  rectangular  mirrors  of  polished  metal, 
or  of  glass  having  the  back  blackened,  are  fixed  at  such  an 
angle  of  incHnation  to  each  other  as  may  be  obtained  by  divid- 
ing 360°  by  the  numbers  3,  4,  5,  6,  7,  8,  &c.  The  cylinder  is 
covered  at  one  end  with  a  circular  plate  of  metal,  having  a 
small  hole  in  the  centre,  while  a  rim  of  metal  is  fitted  over  the 
other  end,  which  is  so  constructed  that  two  circular  pieces  of 
glass  may  be  fixed  in  it  at  a  short  distance  from  each  other, 
having  some  pieces  of  coloured  glass,  beads,  lace,  feathers,  &c., 
in  the  space  between  them.  The  piece  of  glass  that  is  placed 
at  the  extreme  end  of  the  cylinder  should  be  ground  glass,  so 
that  while  the  light  is  admitted  into  the  interior  of  the  instru- 
ment, external  objects  may  be  prevented  from  becoming  per- 
ceptible to  the  observer.  An  angle  of  60°  is  perhaps  the  best 
angle  of  inclination  for  the  mirrors,  as  it  may  be  readily  deter- 
mined, and  affords  a  sixfold  repetition  of  the  pattern,  which 
presents  a  tolerably  uniform  appearance  of  colour  in  all  parts. 
If  the  angle  of  inclination  be  greater  than  60°,  the  pattern  will 
not  be  multipHed  to  so  great  an  extent,  but  if  less,  although 
the  pattern  will  be  repeated  a  greater  number  of  times,  it  will 
lose  considerably  in  brilliancy  at  and  towards  the  parts  where 
the  reflections  of  the   pattern   meet   by  the   frequency  of  the 

multiplication.  In  some 
kaleidoscopes  the  mirrors 
are  made  trapezoidal  in 
form  instead  of  rectan- 
\  gular,  the  broader  ends 
\  being  placed  at  the  lower 
'  end  of  the  tube. 
---■1  The  principle  of  the 
;  kaleidoscope  will  be  un- 
/  derstood  from  the  accom- 
/  panying  figure,  in  which 
the  smaller  circle  ABC 
represents  a  section  of  the 
tube  of  the  instrument, 
and  AB,  AC  sections  of 
the  mirrors,  which  are 
represented  as  inclined  to  each  other  at  an  angle  of  60°.  The 
objects  in  the  space  a  between  the  glasses  are  seen  directly  by 
the  eye,  the  part  of  the  pattern  in  the  space  b  is  formed  by  the 


INSTRUMENTS,  AND  PROCESSES. 


59 


reflection  of  the  objects  in  the  space  a^  in  the  mirror  AB  ;  and 
the  part  C,  by  the  reflection  of  the  objects  in  the  space  a,  in 
the  mirror  AC.  These  reflections  are  again  mutually  reflected 
by  the  opposite  mirrors,  and  form  the  part  de  of  the  pattern 
while  the  images  reflected  in  each  mirror  for  the  third  time 
unite  in  the  part/",  so  as  to  form  a  correspor  ding  appearance 
to  the  other  parts.  It  is  manifest  that  unless  the  angle  at 
which  the  mirrors  are  inclined  be  accurately  determined  the 
reflections  will  not  coincide,  and  the  pattern  will  not  be  com- 
plete in  the  part/! 

Kaleidoscopes  are  made  in  which  the  angle  of  incidence  of 
the  mirrors  may  be  varied  at  pleasure,  and  l:y  the  aid  of  a 
lamp  and  a  system  of  lenses  in  connection  with  the  instrument, 
the  pattern  may  be  projected  on  a  screen  in  an  enlarged  form, 
like  the  image  thrown  from  a  slide  in  a  m  gic  lantern.  A 
pleasing  eff"ect  of  a  similar  nature,  in  which  t'.  e  images  of  the 
original  object  are  multiplied  and  produced  in  different  direc- 
tions, may  be  produced  by  fitting  the  edges  of  three,  four,  or  six 
trapezoidal  mirrors  together,  so  as  to  form  a  1  ollow  prism,  and 
putting  them  into  a  tube  similar  to  that  in  wh  ch  the  two  mir- 
rors of  the  ordinary  kaleidoscope  are  inserted.  Instruments 
of  this  kind,  which 
were  invented  by 
Dr  Roget,  are 
called  polycentral  0 
kaleidoscopes. 

Bevel  -  Wheels. 

— To  strike  out  a 
pair  ofbevel-vvheels. 
The  following  is  the 
method  of  finding 
the  taper  or  bevel 
for  any  line  or 
angle  :  Let  the 
line  AB  represent 
the  shaft  coming 
from  a  wheel,  draw 
the  line  CD  to  in- 
tersect the  line  AB  in  the  direction  intended  for  the  motion 
to  be  conveyed,  and  this  line  CD  will  represent  the  shaft  of 


MISCELLANEOUS  TOOLS, 


the  bevel-wheel  which  is  to  receive  the  motion.  Suppose,  then, 
the  shaft  CD  to  revolve  three  times  whilst  the  shaft  AB 
revolves  once,  draw  the  parallel  line  FE  at  any  moderate  dis- 
tance (suppose  a  foot  by  scale),  then  draw  the  parallel  Une 
FG  at  3  feet  distance,  after  which  draw  the  dotted  line  FH 
through  the  intersection  of  the  shafts  AB  and  CD,  and 
likewise  through  the  intersection  of  the  parallel  line  FE  and 
FG,  to  the  point  H,  then  FH  will  be  the  pitch-line  of  two  bevel- 
wheels. 

Feathering  Float. — The  following  design  for  a  feathering 
float  of  a  paddle-wheel  is  stated  to  have  the  following  advan- 
tages :  — 

The  float  keys  are  in  a  vertical  position  during  an  entire 
revolution  of  the  wheel  ahead  or  astern,  thereby  making  a  clean 

feather.  The 

paddle  -  wheel  is 
no  heavier  than 
the  oldest  style  of 
paddle-wheel.  It 
has  also  a  jour- 
nal-bearer at  the 
extremity  of  the 
shaft,  which  is 
a  decided  im- 
provement on  the 
present  patent 
feathering  -  float 
wheel. 

Suppose  a  ship 

to  lose  her  rudder. 

.    ~~~~~--—-zrzm::z::i^::ir^:^z^        When    all    other 
~-  —  ZZZZZZ~~~~~^.ZZr'  means  of  steering 

are  lost,  the  ship 
can  be  steered  by  this  wheel  by  anghng  the  floats  by  means 
of  a  handle  or  wheel  conveniently  placed  on  deck,  without 
interfering  with  the  speed  of  the  engines. 

Amateur  Lens  Grinding.  —  The  process  of  grinding 
lenses  for  telescopes,  cameras,  &c.,  is  much  more  simple  than  is 
usually  supposed.  If  you  wish  to  grind  a  lens  for  a  telescope, 
first  determine  the  length  of  focus  and  diameter  of  lens  for  the 


INSTRUMENTS,  AND  PROCESSES.  6i 

object  glass,  and  make  a  drawin  gon  paper ;  you  will  then  find 
by  the  drawing  the  thickness  of  glass  required.  We  will  sup- 
pose you  commence  on  a  small  lens  of  li  inches  diameter  and 
of  1 5  or  1 8  inches  focus.  You  must  draw  two  short  lines  par- 
allel to  each  other  i^  inches  apart,  next  open  a  pair  of  compasses 
to  5  inches  and  draw  a  portion  of  that  curve  between  the  lines, 
as  in  fig.  i.  Next  procure  apiece  of  plate  glass  of  the  thick- 
ness shown  by  the  drawing,  and  nibble  it  round  with  a  pair  of 
pliers,  using  a  circular  piece  of  paper  as  a  guide.  Smear  one 
side  of  the  glass  with  pitch,  and  stick  it  on  a  cylinder  of  wood 
of  the  same  diameter  and  3  inches  high  ;  the  crown  lens  will 
then  be  ready  for  grinding. 

The  tools  for  grinding  are  either  of  iron  or  brass,  brass 
being  best.  Take  a  piece  of  thin  zinc  twice  the  width  of  the 
lens,  and  with  the  compasses  at  5  inches  describe  a  portion  of 
that  curve  across  the  zinc,  and  separate  the  zinc  at  the  curve  ; 
you  will  then  have  a  couple  of  patterns  to  get  the  brass  tools 
made  by.  If  you  do  not  possess  a  turning-lathe,  go  to  a  wood- 
turner's and  get  two  patterns  made  to  fit  the  zinc  gauges  ;  the 
patterns  must  have  a  stud  on  each,  as  in  fig.  2,  whereby  to 
fasten  a  bit  of  wood  with  pitch,  to  act  as  a  handle.  After  the 
patterns  are  cast  in  brass  they  ought  to  be  again  turned  to  fit 
the  gauges,  and  finally  rubbed  together  with  emery  until  they 
fit  each  other.  An  amateur  need  not  have  the  tools  much 
larger  than  the  lens. 

Next  procure  from  an  emery-grinder  three  kinds  of  emery, 
\  lb.  of  the  finest  washed  emery,  i  lb.  fine-grained  emery  (ahttle 
coarser  than  flour  of  emery),  and  i  lb.  coarser  still.  Begin  and 
rub  the  glass  with  the  coarse  emery  with  water,  using  the  hol- 
low brass  tool  until  the  glass  is  ground  of  the  same  curve  as 
the  tool.  At  this  stage  you  will  not  be  able  to  see  through  it, 
because  of  the  great  hollows  dug  into  it  by  the  particles  of  the 
coarse  emery.  Therefore  wash  away  all  coarse  particles  and 
rub  again  with  the  next  degree  of  emery,  which  will  put  a  finer 
surface  upon  it.  Wash  all  this  off  the  glass  again,  and  with 
the  finest  emery  put  the  last  grain  on  the  glass  previous  to  pol- 
ishing, using  a  strong  magnifier  to  look  for  scratches  ;  being 
satisfied  the  lens  has  a  fine  equal  grain  all  over  and  free  from 
scratches,  wash  all  clean  and  prepare  the  polisher.  Procure 
4  lb.  of  the  finest  putty  powder,  wann  the  brass  tool  and  smear 
the  inside  of  it  with  pitch  ;   lay  a  piece  of  fine  cloth  over  the 


62  MISCELLANEOUS  TOOLS, 

lens  and  turn  up  the  tool  with  the  pitch  upon  it ;  the  cloth  will 
stick  to  it,  and  when  cold  smear  the  cloth  with  the  putty  powder 
and  water,  rubbing  the  lens  until  on  looking  with  the  eyeglass 
no  trace  of  the  effects  of  the  fine  emery  is  seen.  Warm  the 
lens  before  a  fire,  slide  it  off  the  wooden  holder,  wash  the  pitch 
from  the  lens  with  turpentine,  spirits  of  wine,  or  other  solvent, 
and  you  will  have  ground  and  polished  a  plane  convex  lens  of 
lo  inches  focus,  it  being  a  rule  in  optics  that  a  lens  ground  on. 
one  side  only  will  have  its  focus  at  twice  the  radius  ;  but  ground 
on  both  sides,  will  have  its  focus  at  the  radial  point.  You 
must  now  turn  the  other  side,  taking  care  of  the  feather  edge 
as  you  approach  it,  by  not  going  so  far  with  the  coarse  emery. 
When  the  second  side  is  finished,  you  will  have  a  crown  lens 
of  5  inches  focus.  To  make  the  terrestrial  telescope  an  achro- 
matic one,  add  a  concave  lens  of  flint  glass  to  it. 

We  will  suppose  the  crown  lens  is  finished  ;  but  as  its  form 
is  thick  in  the  centre  and  thin  at  the  edge,  it  will  be  similar  to 
a  circular  prism,  and  would  show  all  objects  with  the  chromatic 
colours  ;  another  lens  must  therefore  be  ground  that  is  thick 
at  the  edge  and  thin  in  the  centre,  to  counteract  the  dispersive 
power  of  the  convex  lens,  and  as  flint  glass  has  in  general  twice 
the  specific  gravity  of  crown,  and  consequently  has  twice  the 
dispersive  power,  it  will  of  course  do  the  same  amount  of 
work  with  one-half  the  angle  of  the  crown  lens,  as  in  fig.  3, 
and  so  reunite  the  coloured  rays  and  form  again  white  light. 
Accordingly  grind  one  from  the  bottom  of  a  flint-glass  tumbler. 
Grind  it  on  a  flat  stone  to  the  proper  thickness,  and  also  get  it 
to  the  diameter  by  taking  a  strip  of  sheet  iron  an  inch  wide 
and  bend  it  so  as  to  form  a  collar  ;  by  putting  emery  and  water 
betwixt  the  collar  and  the  glass,  by  pinching  the  collar  with 
the  fingers  while  the  glass  revolves  on  the  nose  of  a  wooden 
chuck,  it  will  be  reduced  in  a  few  minutes.  After  it  is  the  pro- 
per diameter  and  thickness,  commence  rubbing  it  on  the  convex 
tool  and  finish  it  in  the  same  manner  as  before  ;  you  will  now 
have  a  concave  side  finished  which  will  fit  the  convex  lens  ; 
take  it  off  the  holder  and  turn  the  last  side  up,  and  now  learn 
that  it  is  a  very  difficult  thing  to  grind  and  polish  a  surface 
truly  flat,  so  that  you  had  better  grind  the  last  side  concave 
upon  a  tool  of  a  large  radius,  say  30  inches.  The  two  glasses 
must  then  be  cleaned  and  made  warm  gradually  before  a  fire  ; 
a  drop  or  two  of  Canada  balsam  being  let  fall  into  the  concave 


INSTRUMENTS,  AND  PROCESSES. 


63 


lens,  drop  the  convex  one  on  it,  press  the  air  bubbles  out,  and 
when  the  balsam  sets  you  will  have  a  small  achromatic  lens. 
The  streaks  or  strise  in  the  bottoms  of  tumblers  are  not  of 
so  much  importance  in  a  terrestrial  telescope.  Some  of  the 
best  photographic  lenses  have  air  bubbles,  and  some  when 
accidentally  cracked  work  quite  as  well  as  before.  In 
astronomical  telescopes  the  glass  must  be  of  the  purest 
kind. 

Now  take  your  compound  lens  and  try  its  focus  by  the  sun, 
and  make  the  tube  3  or  4  inches  longer,  so  as  to  support  the 
magnifying  tube  called  the  eye-piece.  The  object  lens  will  form 
an  image  of  anything  within  the  tube,  say  the  clock-dial  of  a 
distant  church — the  tube  called  the  eye-piece  merely  magnifies 
this  image,  and  a 
variety  of  eye- 
pieces may  be 
used  for  the  same 
object  glass,  ac- 
cording as  a  high 
or  a  low  power 
is  required ;  in 
short,  a  telescope 


^ 


may  be  compared  to  a  camera  obscura,  with  a  microscope 
attached,  to  enlarge  the  image  formed  by  the  object  glass. 

Now  then  about  the  eye-piece.  The  subjoined  formula  may 
be  taken,  because  the  lenses  for  it  are  all  pianos,  so  that  you 
will  only  have  to  grind  one  side  of  them,  if  a  piece  of  plate 
glass  be  used.  Focus  of  front  lens  ifths,  ditto  of  second  lens 
ifths,  ditto  of  third  lens  ifths,  ditto  of  lens  next  the  eye  i^th. 
The  first  and  second  lenses  may  be  a  little  under  \  inch  dia- 
meter ;  the  third  or  field  lens  may  be  a  little  more  than  J  inch 
diameter  ;  and  the  lens  next  the  eye  may  be  about  fths  dia- 
meter. 

Make  two  short  tubes  i|  inches  long  (they  are  called  cells), 
and  fix  your  lenses  to  each  end  of  the  two  tubes  or  cells,  then 
take  a  tube  called  the  eye-piece  6i  inches  long,  and  slide  the 
two  cells  into  each  end  of  this  tube  ;  you  will  then  have  an  eye- 
piece which  must  slide  into  the  larger  tube  to  focus  on  the 
image  formed  by  the  object  glass. 

In  the  following  machine  for  grinding  and  polishing  speculum, 
A  is  the  base, /is  the  worm  shaft  which  drives  the  worm-wheel 


64 


MISCELLANEOUS  TOOLS, 


b,  and  this  is  bolted  to  a  spur-wheel  c,  both  of  ninety.  They 
turn  on  a  stud  g,  and  are  made  with  a  circular  flange  near  their 
periphery,  the  lower  surface  of  which  bears  upon  a  trued  part 
A,  and  the  upper  gives  a  firm  support  to  the  speculum  and  its 
cistern  (not  shown  in  the  engraving).  The  wheel  c  drives  an- 
other of  fifty-two  not  seen,  but  attached  to  the  lower  surface  of 
the  cam  d ;  in  the  groove  of  this  is  engaged  a  pin,  fixed  in  the 
lower  surface  of  the  cam  lever  e,  which  is  thus  made  to  vibrate 
as  the  cam  revolves.  The  lever  has  a  series  of  holes,  to  any 
of  which  can  be  attached  one  end  of  a  link,  whose  other  end 
is  connected  with  the  upper  or  sliding-plate  B,  which  thus  by 
the  rotation  of  the  cam  is  made  to  vibrate  to  and  fro  according 
to  any  required  law,  the  actual  law  being  that  of  uniform 
motion.     The  plate   B  carries  a  strong  spindle  h,  on  which 

vibrates  the  arm  i. 
This  arm  can  be  at 
pleasure  either  held 
in  position  by  the 
connecting-link  k,  or 
made  to  vibrate  by 
the  revolution  of  the 
variable  crank  /, 
which  is  driven  by 
a  shaft  at  the  back 
of  the  slide-plate  B. 
The  arm  carries  a 
variable  crank  m.^ 
which  can  be  driven 
either  quickly  by  the 
shaft  and  pulley  n, 
^  or  slowly  by  the 
—  v/orm-wheel  o.  The 
pin  of  77t  drives  the 
polisher.  If  it  be  re- 
quired to  give  Lord 
Rosse's  action,  the  crank  7?i  being  fixed,  and  its  pin  set  central, 
the  crank  /  is  set  in  motion  ;  this  gives  the  primary  stroke,  and 
the  reciprocation  of  the  slide  plate  B  gives  that  of  the  eccentric. 
If  the  worm-wheel  o  be  made  to  act,  at  the  same  time  a  light  lever 
attached  to  in  will  carry  round  with  a  slow  motion  the  polisher  by 
a  stud  projecting  at  its  circumference.      If  it  be  wished  to  have 


INSTRUMENTS,  AND  PROCESSES.  65 

Mr  Lassell's  motion  the  crank  /  is  stopped,  and  it  is  fixed  in 
such  a  position  that  the  pin  of  m  shall  be  at  the  required  dis- 
tance (equal  radius  of  S)  from  the  centre  of  the  speculum,  the 
arm  i  being  held  firm  by  the  link  ;  the  pin  of  7n  is  next  set  to 
the  distance  which  equals  radius  of  G,  and  it  is  driven  by  n. 
In  this  case,  however,  there  is  no  provision  to  secure  the  rota- 
tion of  the  pohsher.  The  eccentricity  can  also  be  given  by 
means  of  B,  and  as  it  can  be  made  to  vibrate  slowly  on  each 
side  of  this  to  any  required  extent,  the  effect  of  Mr  Lassell's 
last  improvement  is  given  to  perfection.  Mr  Grubb  decidedly 
prefers  the  Rossean  action  for  grinding,  but  thinks  the  other 
less  likely  to  fail  in  the  polishing  with  unpractised  hands,  and 
uses  it  himself.  He  begins  with  a  large  eccentricity,  and  gra- 
dually diminishes  it,  which  can  be  done  without  stopping  the 
machine.  His  polisher  is  made  of  wood  with  peculiar  care. 
It  is  formed  by  six  layers  of  mahogany,  each  5-i6ths  of  an 
inch  thick,  and  not  continuous,  but  built  up  of  pieces  3  in. 
square  ;  these  are  only  glued  where  they  cross,  being,  at  least 
in  the  interior,  not  in  close  contact  at  their  edges,  and  the  direc- 
tion of  their  grain  is  varied  as  much  as  possible.  The  disc, 
when  turned  true,  is  plugged  at  the  edges,  varnished,  and  coated 
with  tinfoil  at  the  edge  and  back.  It  is  the  same  diameter  as 
the  speculum.  He  uses  pitch  alone,  rolls  it  in  the  same  manner 
as  Lord  Rosse,  cuts  it  into  squares  of  |  in.,  and  attaches  them 
to  the  surface,  warming  it  by  a  spirit  lamp.  The  machine 
measures  about  3  ft.  every  way,  and  can  work  a  2  ft.  speculum. 

Power  of  Lenses. — The  magnifying  power  of  lenses  is  deter- 
mined by  the  focal  length  and  the  density  of  the  glass  of  which 
they  are  composed.  In  the  case  of  a  telescope,  the  power  may 
be  calculated  approximately  by  the  following  rule  : — If  the 
focus  of  the  eye-piece  be  i  in.,  the  number  of  inches  in  the  focal 
length  of  the  object-glass  will  give  the  magnifying  power  ;  if 
the  eye-piece  be  J-in.  fociis,  the  power  will  be  twice  as  great  as 
with  the  I -in.,  and  so  on  in  proportion. 

The  following  is  a  more  full  explanation  of  the  mode  of  as- 
certaining the  power  of  a  telescope.  First  focus .  it  accurately 
upon  a  distant  object.  If  now  you  turn  the  object-glass  up  to 
the  sky,  and  remove  your  eye  to  some  distance  from  the  eye 
end,  you  will  perceive  a  circular  spot  of  light  upon  the  eyeglass. 
This  is  an  image  of  the  object-glass,  diminished  in  the  exact 

E 


66  MISCELLANEOUS  TOOLS, 

ratio  of  the  magnifying  power  of  the  instrument.  If  then  you 
will  measure  the  precise  diameter  of  this  image  upon  a  finely- 
divided  scale  (assisting  your  vision,  if  necessary,  by  means  of  a 
magnify ing-glass),  and  will  then  ascertain  the  diameter  of  your 
object-glass  by  the  aid  of  the  same  scale  ;  the  division  of  the 
latter  sum  by  the  former  will  give  the  magnifying  power  of  the 
instrument.  Thus,  supposing  that  the  aperture  of  your  object- 
glass  is  2  in.,  and  the  little  circle  of  light  in  the  eye-piece  is 
•08  in.  in  diameter,  the  telescope  will  magnify  exactly  25 
times  ;  or,  assuming  that  you  have  a  i|^-in.  object-glass,  and 
that  the  projected  image  on  the  eye-piece  measures  'oS  in.  in 
diameter,  your  instrument  would  then  magnify  1875  ^"^  about 
19  times  linear.  In  obtaining  the  magnifying  power  of  a  single 
lens,  we  proceed  upon  the  assumption  that  the  distance  of 
distinct  vision  is  10  in.  If  now  we  find  the  focal  length  of 
the  lens,  and  divide  i  o  in.  by  it,  we  shall  get  the  magnifying 
power.  For  example,  a  lens  of  i4n.  focus  magnifies  10  times, 
one  of  ^-in.  focus  20  times,  one  of  ^-in  40  times,  and  so 
on.  The  focal  length  of  a  lens  (when  not  very  short)  may 
be  obtained  with  considerable  accuracy  by  projecting  an 
image  of  the  sun  upon  a  card,  by  means  of  the  lens  whose  focal 
length  is  to  be  measured,  and  when  such  image  is  accurately 
defined,  measuring  the  distance  between  the  lens  and  the  card. 
This  may  be  conveniently  accomplished  by  mounting  the  card 
at  the  end  of,  and  at  right  angles  to  the  length  of,  a  graduated 
scale,  and  sliding  the  lens  along  the  scale  with  its  diameter 
parallel  to  that  of  the  card.  In  the  case,  however,  of  a  lens  of 
very  short  focus,  this  method  becomes  impracticable  ;  and  we 
may  then  have  recourse  to  the  admirable  mode  invented  by 
that  excellent  astronomer,  the  Rev.  T.  W.  Webb,  which  we 
cannot  do  better  than  describe  in  his  words.  "  Three  pieces 
of  cork  are  perforated  by  a  knitting-needle,  so  as  to  slide  along 
it.  To  the  centre  one  is  attached,  in  a  vertical  position,  and 
with  its  axis  parallel  to  the  knitting-needle,  the  lens  to  be 
measured  ;  in  each  of  the  others  is  inserted  a  piece  of  a  sew- 
ing-needle with  the  point  uppermost,  and  having  its  length  so 
regulated  that  a  line  joining  these  points  would  pass,  as  nearly 
as  may  be,  through  the  centre  of  the  lens.  The  cork  discs 
carrying  these  needles  are  then  moved  backwards  and  forwards, 
till  the  inverted  image  of  the  one  needle's  point,  formed  by  rays 
passing  through  the  lens,  is  seen  coincident  and  equally  dis- 


INSTRUMENTS,  AND  PROCESSES. 


67 


tinct  with  the  other  needle's  point,  when  both  are  viewed  at 
once,  through  a  tolerably  strong  magnifier  applied  to  the  eye, 
and  directed  towards  the  lens.  Then  if  the  needle-points  are 
sensibly  equidistant  on  each  side  of  the  lens,  a  condition  which 
can  be  quite  sufficiently  attained  in  the  course  of  a  few  trials, 
it  is  evident  that  they  occupy  the  conjugate  foci,  and  the 
distance  between  them  being  carefully  measured  with  com- 
passes will  be,  as  a  very  simple  proposition  in  optics  will  show, 
four  times  the  amount  of  the  focal  length  of  the  lens  for 
parallel  rays." 


Screw-Propeller. — The  primary  consideration  of  the  appli- 
cability of  a  screw-propeller  to  the  work  it  has  to  do  is  its 
"  pitch,"  that  is,  the  length  in  which  the  screw-whirl  makes  a 
complete  turn  round  its  central  axis,  and  this  "  pitch  "  is  either 
"  finer  "  or  "  coarser,"  as  the  length  of  the  axis  AB  is  shorter  or 
longer  ;  or  in  other 
words,  as  the  turns 
of  the  screw  are 
closer  together  or 
further  apart.  It  is 
evident  that  if  there 
be  no  "  slip,"  that 
is,  if  the  screw  re- 
tains full  hold  upon 
the  water,  as  a  car- 
penter's screw  does 
upon  a  board — that 
in  every  revolution 
of  the  screw-pro- 
peller a  distance  of 
the  length  of  the 
axis  of  the  full  turn 
of  the  screw  will 
have  been  accom- 
plished by  the 
vessel.  If  thus  the 
"  pitch "  of  the 
screw  be  40  ft, 
that  is,  if  from  A  to  B  be  40  ft.,  then  every  full  revolution  of  the 
screw  will,  if  there  be  no  "slip,"  advance  the  vessel  40  ft. 


68  MISCELLANEOUS  TOOLS, 

through  the  water.  From  repeated  experiments  it  has  been 
determined  that  the  best  form  which  can  be  given  to  a  screw- 
is  that  of  two  halves  of  a  spiral  feather,  placed  on  opposite  sides 

of  the  axle  of  the 
?<  screw  in  reverse 
positions  ;  these, 
while  they  occupy 
only  half  the  space 
in  length  which  they  would  otherwise  require,  are  found, 
with  equal  surface,  more  efficient  than  the  continuous  spiral 
formerly  in  use.  The  rectilinear  edges  AB  and  GH  of 
the  ordinary  screws  are  highly  disadvantageous,  on  account  of 
the  shake  of  the  screw  caused  by  the  sudden  and  violent  re- 
actions of  the  disturbed  water  in  that  place  against  the  blades 
of  the  screw  as  they  enter  and  emerge  from  thence — since  the 
whole  of  an  edge  enters  and  leaves  at  once  the  water  on  each 
side  of  the  aperture  ;  within  which  aperture  the  water  is  com- 
paratively in  a  quiescent  state;  but  if  the  leading  edges  of  a  screw 
blade  were  curved  as  A/B,  G/H,  they  would  slide  obliquely  and 
continuously  through  the  water.   .  .   .  The  curved  edges  have, 

beside,  the  advantage  of  throw- 
ing off  any  floating  materials 
that    may    come    in     contact 
^  with    them  "     (Sir     Howard 

Douglas  on  "  Naval  Warfare 
with  Steam  ").  The  pitch  of  screws  vary  with  the  ratio  of  the 
circle  described  by  the  screw  to  the  midships  section. 

For  1-bladed  screws  {MoleswortHs  formulcE). 

Ratio   of  screw's  disc  to  "j 

midships  section  being  V6      5      4^4313212 

I  to  I 

Ratio  of  pitch  to  the  dia-  ^ 

meter    of    screw    is    i  >-    -8  i'02  I'l  i  1-2  1-27  1-31  1-4  1-47 

to  3 

Gyroscope. — To  make  a  gyroscope,  get  a  brassing  AAA, 
about  5  in.  in  diameter,  J  in.  broad,  and  \  in.  thick, 
having  a  projection  B  at  one  part.  On  the  flat  surface  of 
the  ring,  near  to  B,  must  be  a  small  lump  C,  also  another 
just  opposite  D.    These  must  be  screwed  on  by  two  small  screws 


INSTRUMENTS,  AND  PROCESSES. 


69 


each,  and  are  for  the  purpose  of  holding  the  spindle  EE,  which- 
must  turn  freely  on 
these  centres.  At 
the  middle  of  this 
spindle  must  be 
fixed  the  disc  FF, 
which  should  be 
about  two  or  three 
times  as  heavy  as 
the  ring.  A  hole 
must  be  drilled 
through  this  spindle 
at  some  convenient 
part  for  the  string. 
The  method  of  us- 
ing is  this  : — The 
hole  in  the  spindle  must  be  threaded  with  a  piece  of  string,  and 
the  disc  turn  round, 
winding  the  string 
up  the  same  as  is 
done  with  a  hum- 
ming-top. The  string 
is  then  drawn  sharp- 
ly out,  and  the  disc 
made  to  spin  rapidly 
round.  If  the  in- 
strument is  then  sup- 
ported by  a  loop  of 
string,  or  on  a  point 
at  B,  it  will  (instead  of  falling  to  the  ground,  as  might  be  supposed) 
remain  in  a  horizontal  position,  moving  round  B  as  a  centre. 
(See  engraving.)     The  ring  AAA  should  be  placed  horizontally. 

Another  method,  identical  in  principle,  but  differing  slightly 
in  detail,  is  as  follows  :  — 

The  wheel  is  brass,  turned  to  the  shape  shown  in  sketch  ; 
the  axis  of  the  wheel  is  steel.  The  wheel  is  first  bored  for  the 
reception  of  spindle  ;  then  the  spindle  is  driven  in  after  being 
cut  to  its  proper  length,  and  drilled  with  very  fine  centres  ;  it  is 
then  turned  on  its  own  centres  perfectly  true.  A  lathe  with 
two  dead  centres  is  the  best  for  turning  it.  After  it  is  turned, 
the  ends  of  the  spindle  are  properly  hardened.     A  small  hole 


\  rr 


\j 


-ri 


70 


MISCELLANEOUS  TOOLS, 


is  inserted  in  one  end  of  spindle  for  reception  of  twine.      The 

way  to  harden  the 
ends  of  the  spindle 
is  this : — Get  a  plate 
of  iron  about  |  in. 
thick,  bore  a  hole  in 
it  just  large  enough 
to  admit  the  end  of 
the  spindle,  then 
place  it  on  the  fire 
(a  small  slow  fire). 
Fill  the  upper  recess 
of  wheel  with  cold 
water,  to  keep  the 
brass  cold. 

The  ring  is  made 
of  brass,  is  about  \ 
in.  thick  and  \  in.  broad,  with  two  bosses  in  the  direction  of 
the  centre  line.  These  bosses  are  bored  and  tapped  about 
3-i6ths  or  \  in.  for  the  reception  of  steel  screws.  The  ring  is 
bored  out,  and  filled  up  until  the  ring  is  equally  balanced  ;  if 
the  ring  is  not  balanced,  it  will  not  hang  horizontally  as  it 
rotates  round  the  point,  but  the  heavy  side  will  hang  down,  and 
cause  it  to  "waver,"  One  steel  screw  is  ground  to  a  sharp 
point  at  both  ends,  with  a  square  shoulder  to  screw  it  in  with. 
The  point  of  these  screws  are  hardened,  the  other  screw  has  a 
square  head  with  a  sharp  centre  drilled  in  it.  A  small  steel 
bracket  is  secured  by  this  screw,  as  shown  in  sketch.  This 
bracket  has  a  sharp  centre  in  it  made  with  a  sharp  centre 
punch  to  rest  on  the  point  of  upright  spindle  ;  this  bracket  is 
also  hardened.  The  upright  spindle  is  made  of  steel,  screwed 
into  a  base  of  lead,  as  shown  in  sketch.  The  spindle  is  turned 
and  ground  to  a  very  sharp  point,  then  properly  hardened. 
The  wheel  will  not  only  revolve  horizontally  round  the  point, 
but  will  revolve  when  placed  perpendicular  by  placing  the 
centre  in  head  of  screw  (as  shown)  on  the  point  of  spindle  ;  it 
will  also  spin  on  the  point  of  the  other  screw  if  placed  on  a 
plate  or  any  smooth  surface.  After  the  points  of  spindle  or 
axis  of  wheel  are  hardened,  the  points  of  screws  being  soft,  the 
wheel  is  spun  round  a  few  times  to  grind  the  centres  to  fit 
each  other.     After  that  the  points  of  screws  are  hardened. 


INSTRUMENTS,  AND  PROCESSES.  71 

Telescope,  to  Make. — To  make  a  Galilean  telescope  the  fol- 
lowing articles  are  required: — A  double-convex  lens  of  5 -ft.  focus 
and  2-in.  diameter;  a  double-concave  of  i-in.  focus  and  about 
^-in.  diameter  ;  a  large  tube  of  tin-plate,  zinc,  or  cardboard,  4-ft. 
8  in.  long,  and  3  in.  diameter  ;  a  cylinder  of  wood,  turned  to  fit 
tightly  in  one  end  of  the  large  tube,  and  having  a  central  hole 
of  about  I  in.  diameter  bored  through  it ;  and  a  small  tube  for 
the  eyeglass  6  in.  or  8  in.  long,  and  of  just  sufficient  diameter 
to  slide  into  the  central  hole  of  the  cylinder.  The  section  will 
explain  the  use  of 
these  articles.  A  I 
is  the  large  tube ; 

B,  the  object-glass  ; 

C,  the  wooden 
cylinder ;  D,  the 
eye-tube  ;   and  E,  the  eyeglass. 

The  object-glass  and  eyeglass  must  be  at  a  distance  from  each 
other  equal  to  the  difference  of  their  focal  lengths,  and  the 
power  will  be  equal  to  the  number  of  times  the  focal  length  of 
the  eyeglass  is  contained  in  that  of  the  object-glass.  In  the 
present  case  this  is  60. 

Tin-plate  is  the  best  and  cheapest  material  for  the  tube,  but 
in  reality  it  matters  little  of  what  it  is  made,  so  that  it  be 
straight  and  not  too  heavy.  Its  interior  should  be  coated  with 
a  mixture  of  lampblack  and  turpentine,  A  diameter  of  three 
inches  is  best,  in  order  to  decrease  the  liability  of  flexure  which 
very  narrow  tubes  possess,  and  also  to  give  more  facihty  in 
mounting  the  object-glass. 

In  purchasing  this  article,  it  is  much  the  better  plan  to  buy 
one  from  the  optician  already  centred  ;  but  if  such  cannot  be 
obtained,  one  should  be  selected  the  edges  of  which  possess  an 
uniform  thickness.  In  such  a  one  the  optic  axis  will  not  be 
very  far  from  the  actual  centre.  In  mounting  it,  glue  it  be- 
tween two  circular  rings  of  cardboard,  whose  outer  diameters 
just  fit  the  large  tube,  and  with  a  central  circle  cut  out  of  each 
I J  in.  in  diameter.  The  lens  must  be  fastened  between  these, 
so  that  its  centre  will  coincide  as  nearly  as  possible  with  the 
centres  of  the  cardboard  circles.  It  should  be  placed  an  inch 
or  two  within  the  tube,  as  it  is  then  better  defended  from 
injury  than  when  at  the  very  extremity. 

A  ring  of  iron  wire  soldered  within  the  tube  will  do  to  rest 


72  MISCELLANEOUS  TOOLS, 

the  mounted  lens  upon,  and  another  ring  of  wire  pushed  down 
upon  it  will  hold  it  firmly  in  its  place.  These  rings  are  shown 
in  the  section  by  the  four  black  dots,  two  on  each  side  the 
cardboard  mounts  of  the  object-glass.  The  eyeglass  may  be 
fitted  in  a  similar  manner.  The  length  of  the  wooden  cylinder 
should  not  be  less  than  2  in. 

In  making  the  Galilean,  or  any  other  telescope,  the  one 
great  thing  to  be  attended  to  is  to  keep  the  centres  of  all  the 
lenses  coincident  with  the  axis  of  the  tube,  and  their  planes 
at  right  angles  to  it.  Inattention  to  this  is  certain  to  injure 
the  perfornjance  of  the  telescope,  however  good  its  glasses  may 
be.  Most  of  the  failures  in  amateur-made  telescopes  that  have 
come  under  my  eye  have  arisen  from  this  cause.  It  will  be 
seen  that  a  first  requisite  to  success  on  this  point  is  to  make 
the  tube  perfectly  straight  and  rigid,  and  its  section  perfectly 
circular.  The  wooden  cylinder  should  be  turned  perfectly  true, 
the  hole  drilled  through  it  perfectly  central,  and  not  the  slightest 
lateral  play  allowed  to  the  small  eye-tube.  Though  in  none 
of  these  particulars  is  absolute  perfection  attainable,  yet  arny 
one  making  a  telescope  should  never  forget  that  the  nearer 
he  can  approach  it,  the  more  satisfactory  will  his  instrument 
be. 

There  is  one  point  to  which  the  attention  of  all  beginning  to 
handle  lenses  should  be  directed,  and  that  is,  to  avoid  wiping 
and  rubbing  as  much  as  possible.  Remove  any  dirt  that  may 
fall  on  the  glass  by  blowing  it  away,  and  remember  that  the 
definition  of  a  telescope  is  much  less  injured  by  a  deposit  of 
dust  on  the  object-glass  than  by  the  numberless  small  scratches 
which  much  wiping  invariably  causes. 

The  cost  of  this  telescope  is  as  follows  : — Object-glass, 
2s.  ;  eye-glass,  is.  ;  tube  (if  home-made)  of  tin-plate,  is. 
6d.  ;  wooden  cylinder,  lampblack  and  turpentine,  say  6d. 
more  ;  total,  5  s.  It  will  show  well  Jupiter's  moons,  and 
more  conspicuous  belts,  Saturn's  ring,  and  one  or  two  of 
his  moons  on  favourable  nights,  the  phases  of  Venus  and 
Mars,  the  hills  and  valleys  of  the  lunar  surface,  and  the 
solar  spots  splendidly,  together  with  many  nebulae  and 
double  stars. 

A  stand  for  our  telescope  must  not  be  forgotten.  A  poor 
telescope  on  a  good  stand  is  greatly  superior  to  a  good  tele- 
scope or  a  poor  stand. 


INSTRUMENTS,  AND  PROCESSES. 


73 


Telescope  Stand. — An  excellent   stand  was  made  a  few 
years  ago  on  the  following  model :  — 

It  is  made  of  deal ;  the  advantages  are  steadiness,  the  work 
being  thrown  into  triangles,  the  steadying  cords  and  weights 
checking  all  vibra- 
tion. The  spindle 
may  be  placed  and 
adjusted  to  the 
position  of  a  polar 
axis,  and  by  fix- 
ing pins  on  per- 
manent blocks  in 
the  ground,  with 
brass  sockets  on 
the  bottom  of  the 
legs,  the  stand 
may  be  always 
placed  in  the  same 
position.  There 
may  be  various 
changes  in  the 
position  of  the 
cords  and  weights. 
The  first  use  made 
of  them  was  to 
steady  the  end  of 
the  telescope  put 
through  a  window 
by  cords  and 
weights  in  the 
position  figured,  where  CCC  are  cords,  and  T  telescope. 

Made  in  two  movable  parts,  feet  of  one 
A,  of  the  other  BB  ;  hinged  together  at 
HH  ;  E,  screw-bolt  ;  F,  cross-piece  from 
fore  to  hind  part ;  CCC,  steadying  cords, 
with  weights  W  and  W^,  the  latter  running 
on  pulley  P  ;  SS,  spindle  turning  in  brass 
bearings  ;  Y,  iron  supporting  the  sides  of 
telescope  on  two  screw-pins. 

The  Y  spindlehead  suspending  the 
sides   of  the  telescope  is  much   steadier   than 


a  swivel-joint 


74 


MISCELLANEOUS  TOOLS, 


under  the  telescope  tube. 
6  ft. 


Height  to  pivots  of  telescope  about 


A  good  "Dead-Black"  for  Telescopes,  Cameras,  &c.,  is 

somewhat  troublesome  to  make.  Take  some  ordinary  French 
polish,  or  dissolve  some  shellac  in  methylated  spirit,  and  add 
lampblack  until  the  happy  medium  is  attained,  that  when 
applied  to  a  piece  of  warm  brass,  it  shall  dry  a  dead-black.  If 
it  dries  with  a  dead-black  surface  which  rubs  off,  more  polish 
or  shellac  must  be  added  ;  if  it  dries  bright,  more  lampblack. 
Another  plan  is  to  put  the  brass-work  into  dilute  nitric  acid 
to  take  off  any  oxide,  and  put  it  into  a  solution  of  bichloride 
of  platinum  ;  when  it  has  changed  colour,  brush  the  work 
sharply  up  with  a  brush  and  dry  blacklead,  after  which 
lacquer  it. 

A  third  method  is  to  take  lampblack  and  mix  it  with  water, 
and  just  sufficient  size  to  keep  it  from  rubbing  off. 

To  Cut  Microscopic  Sections  of  Wood. — The  following 
engraving  is  half-full  size  of  a  machine  for  cutting  thin  sections 
of  objects  for  microscopic  examination,  which  has  been  in  use 
for  some  years,  and  which  is  one  of  the  cheapest,  simplest,  and 

most  effectual  that  could  be  de- 
vised. AB  represents  a  piece 
of  J-in.  brass  tubing,  with  a 
flange  CD,  of  about  2\  in.  in 
diameter,  at  the  end  A,  and  with 
a  female  screw  tapped  at  the  end  B 
to  receive  the  capstan-headed  screw 
E  ;  F  is  a  brass  plug  or  piston, 
which  is  driven  up  the  tube  in  a 
perfectly  obvious  way  by  the  screw 
E.  This  screw  has  30  threads  to 
the  inch.  A  razor  ground  flat  on 
one  side,  to  slide  accurately  over 
the  upper  surface  of  the  flange  CD 
(which  must  itself  be  quite  true^, 
completes  the  apparatus. 
The  mode  of  using  it  is  simply  this  : — The  wood,  or  other 
substance  of  which  a  section  is  to  be  made,  is  to  be  driven 
down  the  tube  at  A.  The  screw  is  then  turned  until  the  object 
to  be  cut  projects  slightly  above  the  mouth  of  the  tube,  and  the 


INSTRUMENTS,  AND  PROCESSES. 


75 


razor  is  slidden  across  it,  taking  off  a  slice  of  the  material,  and 
reducing  it  to  a  level  with  the  surface  of  the  flange.  By  turn- 
ing the  screw  again  to  a  small  extent,  and  again  sliding  the 
razor  (which  should  now  be  wetted)  across  the  flange,  it  is 
perfectly  clear  that  we  may  remove  a  slice  of  wood  of  any 
tenuity  we  please,  its  thickness  being  regulated  by  the  extent 
to  which  the  screw  is  turned.  The  sections  thus  made  may 
be  conveniently  washed  off  into  a  cup  of  water,  to  be  taken  out 
as  required. 

Several  more  or  less  elaborate  pieces  of  mechanism  may  be 
purchased  at  the  optician's,  at  prices  varying  from  15s.  to  ^4  ; 
but  none  will  do  their  work  more  effectually  than  that  described, 
which  ought  not  to  cost  more  than  six  or  seven  shillings. 

Another  Cutting-Machine. — B,  a  block  of  wood  with  a  hole, 
into  which  is.  fitted  C,  a  brass  tube;  D,  a  brass  plug  or  lift 
accurately  fitted,  and  having  two  studs  S  to  work  in  correspond- 
ing slots  in  C  ;  E,  an  iron  pin  without  head  fixed  with  D — pitch 
25   threads  ;     H,  a 


brass  nut,  the  top 
fitted  to  C,  through 
it  works  E.  The 
nut  has  two  collars 
or  flanges,  M  and  N, 
and  between  is  O,  a 
split  collar,  which  is 
screwed  on  to  the 
box  B.  This  collar 
keeps  the  nut  in 
place,  and  yet  allows 
it  to  be  turned  ;  XX 
ing  screw  to  keep 


8 


.,  two  studs  to  turn  the  nut  H  ;   Z,  a  bend- 
object  in   place  ;   T,  a  bench  clamp ;    A, 
brass  plate  on  which  to  cut. 

The  great  advantage  in  this  construction  is  the  pin  and 
plug  moving  (up  and  down)  vertically  without  turning  or  twist- 
ing in  the  tube  or  cylinder  more  than  the  fractional  ease  of  the 
slots  in  which  the  studs  work.  The  plug  being  fitted  nicely  to 
the  cylinder,  and  the  pin  fixed  into  it,  and  the  nut  working 
nicely  in  the  collar,  gives  a  firmness  not  to  be  obtained  in 
machines  in  which  the  pin  turns.  The  pitch  of  the  screw  is 
25,  therefore  a  quarter  turn  of  the  nut  gives  the  looth  part, 
and  an  eighth  turn  the  200th  part  of  an  inch. 


76 


MISCELLANEOUS  TOOLS, 


The  cutter  is  a  spokesbave  with  the  ends  turned  straight 
and  fitted  into  handles.  The  hollow,  or  under  side,  on  the  plate 
is  used,  the  face  of  the  plate  being  very  flat  and  straight.  The 
inventor  of  this  machine  prefers  the  under  side  of  a  cutter  hollow, 
not  flat,  as  recommended  by  many.  There  is  less  adhesive 
resistance,  and  no  slipping,  as  with  the  perfectly  flat  surface. 


Hints  on  the  Microscope. — A  mechanical  stage  is  a  sine 
qua  non,  and  plenty  of  room  beneath  it  for  the  illuminating 
apparatus.  This  stage  should  not  be  thicker  than  the  |th  of 
an  inch,  a  mere  plate  with  a  wide  hole,  say  2  in.  square,  the 
milled  hands  and  tangent  screws  being  all  placed  behind  the 
frame,  easy  to  get  at,  and  out  of  the  way  of  the  objects. 

This  form  does  not  admit  of  a  circular  motion,  but  we  have 
not  yet  learnt  the  real  value  of  such  a  motion,  while  the  advan- 
tages of  a  thin  stage  are  unspeakable. 

A  Coddington  lens,  or  an  eye-piece  on  Kelner's  principle, 
makes  a  good  condenser,  and  only  cone  eye-pieces  are  worth 
using  ;  if  you  desire  higher  magnification,  either  get  a  higher 
power  or  lengthen  your  tubes. 

An  economic  condenser  made  by  an  amateur  microscopist 
is  shown  in  the  following  sketches  : — 

Fig.    I. — A,   spot-lens,    about 


1-in. 


focus ;  B,  achromatic 
spot-lens,  about  i^- 
in  focus,  placed 
at  about  the  same 
distance  as  in  a 
Kelner  eye-piece,in 
a  tube  C,  screwed 
in  a  flat  ring  of 
metal  D,  which  is 
supported  on  a  flat 
p'^  plate  G,  secured 
by  a  holdfast  E, 
allowing  room  be- 
tween for  a  dia- 
phragm F,  to  re- 
volve freely  on  its 
axis,  which  is  done 

by  a  screw  passing  through  a  holdfast  into  the  plate  G  ;    H  is 

a  tube  |-in.  long  for  carr}dng  polariscope. 


INSTRUMENTS,  AND  PROCESSES. 


77 


Fig.  2. — Diaphragm. — A,  for  direct  light  ;  B,  for  difficult 
test-objects;  C, dark- 
ground  illuminator ; 
D,  small  aperture, 
with  shutter  E,  hav- 
ing a  small  hole  in 
it.  The  features 
presented  by  this 
condenser  are  that 
it  is  applicable  for 
both  high  and  low 
powers,  can  be  used 
by  merely  sliding  it 
into  a  tube  under 
the  stage,  and  never 
need  be  removed 
except  for  cleaning. 
For  a  micrometer, 
the  following  plan, 
which  any  one  can 
effective. 

Find  the  exact  size  of  your  field  by  looking  at  a  footrule 
laid  beside  your  stage  with  the  one  eye,  while  the  other  is 
applied  to  the  pipe ;  say  it  gives  i  ft.  Now  put  the  rule 
on  the  stage,  and  see  how  many  divisions  of  an  inch  fill  the 
field  ;  suppose  it  is  |th  in.  in  this  assumed  case,  this  object- 
glass,  with  the  same  length  of  tube,  will  magnify  96  linear, 
therefore  all  objects  viewed  will  be  increased  to  that  extent. 

Your  instrument  must  be  steady,  the  fine  adjustment  very 
fine,  the  spring  very  light,  and  the  tube  into  which  the  object- 
glass  is  screwed,  and  which  the  adjustment  moves,  very  tioie, 
and  also  very  easy  to  lift,  so  that  a  coarse  hand  may  neither 
damage  the  instrument  nor  object,  and  each  turn  ought  to  raise 
or  depress  it  i-iooth  of  an  inch,  and  so  become  a  micrometer  to 
measure  depth. 

For  a  camera  lucida,  get  two  bits  of  neutral-tinted  glass,  and 
place  them  at  an  angle  of  45°  before  the  eye-lens.  A  little 
practice  will  enable  you  thus  to  use  the  binocator,  and  the  ease 
to  the  eyes  is  immense. 

For  polariscope,  use  a  short  white  Nicol's  prism,  set  so  as  to 
turn  in  a  tube,  and  to  which  tube  you  can  screw  the  object-glass. 


adopt,  and  requires  no  apparatus,  is  quite 


78  MISCELLANEOUS  TOOLS. 

A  number  of  large  squares  (i6  or  20,  ^  size)  such  as  we  cover 
objects  with,  form  the  best  analyser.  The  polariscope  is,  how- 
ever, except  in  the  hands  of  the  chemist,  pretty  much  a  toy. 

It  is  a  great  mistake  to  have  slides  in  any  numbers  ;  have 
many  compressioriums,  lots  of  bottles  and  small  tanks,  and 
eschew  diatomacae  valves.  Wherever  you  go,  carry  a  nail  or 
two  and  an  old  lucifer-box,  a  walking-stick  and  a  bit  of  string  ; 
tie  a  vial  to  the  stick,  and  dip  from  top,  bottom,  and  middle  of 
every  permanent  water-hole  ;  when  you  find  a  small  insect,  put 
him  in  the  box.  Your  walks  will  be  all  pleasure,  and  your 
evenings  both  pleasure  and  instruction.  Make  for  yourself  all 
your  apparatus  ;  never  mind  the  polishing,  but  make  all  good 
and  true  as  to  the  brass,  &c. ;  put  all  the  polish  on  the  glasses,  and 
begin  with  a  2-in.  and  a  ^-in.  ;  the  glass  of  moderate  angle  is 
much  preferable  to  the  ground  1708  lenses.  These  latter  can- 
not be  illuminated  by  annular  condensers,  and  thus  the  prettiest 
and  pleasantest  way  of  viewing  an  object  is  lost.  The  "  celia  " 
of  the  Feloscalaria  ornata,  for  instance. 

Keep  in  your  small  tanks  a  few  roots  of  Zitella,  and  Valis- 
neria  :  both  are  good  for  the  infusoria,  and  charming  objects  in 
themselves.  From  the  air,  ground,  river,  pond,  or  sea,  get 
your  objects ;  remember  that  slides  once  seen  become  tire- 
some. 

Mathematical  Instruments,  &c.  —  All  polished  steel 
instruments  are  best  kept  from  rust  by  enclosure  in  wool. 
The  high  conducting  power  of  metal  causes  easy  condensation 
of  moisture  (the  cause  of  rust) ;  wool  is  a  good  non-conductor 
of  heat  or  cold. 

Weather- G-lass. — Various  experimental  barometers  have 
from  time  to  time  been  constructed,  all  with  the  view  of  com- 
bining economy  with  simplicity  in  a  greater  degree  than  is 
obtained  in  the  ordinary  weather-glasses  of  commerce. 

A  simple  barometer  may  be  made  as  follows  : — 

A  wide-mouthed  glass  bottle  is  filled  with  ordinary  drinking 
water  up  to  the  point  indicated  by  the  letter  A  ;  into  this  is 
dipped  an  inverted  clean  oil-flask,  the  extremity  of  the  neck 
being  allowed  to  dip  just  below  the  surface  of  the  water. 

The  flask  should  be  inverted  quite  empty  during  wet  weather, 
and  as  long  as  the  atmosphere  remains  in  a  stormy  condition 
no  change  in  the  water  takes    place;    but   immediately  the 


CEMENTS  AND  GLUES. 


79 


weather  becomes  finer,  the  water  will  rise  in  the  neck  of  the 
inverted  oil-flask,  and  if  a  continuance  of 
fine  weather  be  probable,  will  rise  to  the 
point  indicated  by  letter  B. 

This  simple  contrivance  gives  sure 
and  early  warning  of  the  approach  of 
rain. 

The  principle  upon  which  this  little 
weather-glass  acts  is  exactly  similar  to 
that  of  the  ordinary  mercury  barometer, 
the  rise  and  fall  of  the  water  due  to  the 
respective  increase  or  decrease  of  atmo- 
spheric pressure. 

By  dividing  the  neck  AB  into  six  or 
eight  divisions  with  the  aid  of  a  diamond 
or  piece  of  flint,  and  then  marking  the 
lines  so  cut  with  ink,  an  approximate 
graduation  of  degrees  of  pressure  may 
easily  be  obtained. 

Cements  and  Glue. — Below  are  given  a  variety  of  cements 
to  join  anything  from  a  millband  to  a  knife-handle.  The 
relative  proportions  are  given  in  each  case,  and  the  directions 
for  mixture  and  application  must  be  strictly  followed. 

Cement  to  join  Leather  or  India-Rubber. — To  unite  pieces 
of  leather  or  india-rubber,  use  either  of  the  following  : — 

One  ounce  of  caoutchouc  cut  in  thin  slices,  and  placed 
in  a  tinned  sheet-iron  vessel,  with  six  or  seven  ounces  of 
sulphide  of  carbon  ;  the  vessel  is  then  to  be  placed  in  a  water- 
tank,  previously  heated  to  about  86''  Fahr.  To  prevent  the 
solution  from  becoming  thick  and  unmanageable,  mix  with  a 
solution  consisting  of  spirits  of  turpentine,  in  which  half  an 
ounce  of  caoutchouc  in  shreds  has  been  dissolved  over  a  slow 
fire,  and  then  a  quarter  of  an  ounce  of  powdered  resin,  from  an 
ounce  and  a  half  to  two  ounces  of  turpentine  being  afterwards 
stirred  in  in  small  quantities. 

Put  a  small  quantity  of  virgin  or  native  rubber,  cut  into 
shreds,  into  a  wide-mouthed  bottle,  and  pour  over  it  benzine 
until  the  bottle  is  about  three-quarters  full.  The  rubber  will, 
if  often  shaken,  in  a  few  days  assume  the  consistency  of  honey, 
with  a  thick  sediment  at  the  bottom.    If  not  thoroughly  dissolved 


8o  CEMENTS  AND  GLUES. 

more  benzine  must  be  added.  The  benzine  must  be  of  the  best 
quahty,  and  free  from  oil.  Except  when  using,  the  bottle  con- 
tainiiig  this  cement  must  be  kept  well  corked. 

This  cement  dries  in  a  very  short  time,  and  three  coats 
applied  in  the  usual  manner  will  serve  to  unite  anything  either 
in  leather  or  rubber. 

Dissolve  gutta-percha  (i  oz.)  in  bisulphide  of  carbon  (6  oz). 
Apply  the  solution  to  both  surfaces  to  be  joined,  allow  to 
dry,  which  will  take  a  few  minutes  ;  then  place  a  hot  iron 
near  enough  to  just  melt  the  gutta-percha  on  both  surfaces  ; 
immediately  press  them  well  together,  through  rollers  or  under 
pressure.  Leather  fastened  in  this  way  does  not  need  sewing. 
[A  hose-pipe  can  only  be  joined  in  one  way — the  broken  part 
cut  out,  the  edges  made  square,  a  short  piece  of  brass  tube 
— fitting  the  hose  tightly — inserted,  and  the  two  ends  brought 
together  over  it,  and  bound  tightly  with  copper  wire]. 

Another  excellent  cement  for  millbands,  &c.,  is — To  4  oz.  of 
bisulphide  of  carbon  add  \  oz.  india-rubber,  and  \  oz.  gutta- 
percha, cut  in  shreds  ;  place  the  whole  in  a  half-pint  bottle, 
well  corked.  It  will  dissolve  without  heat  in  about  12  hours, 
and  be  ready  for  use.  The  parts  to  be  joined  must  be  thinly 
coated  with  the  solution,  and  allowed  a  few  minutes  to  dry  ; 
then  heat  to  melting,  very  quickly  place  together,  and  well 
hammer  the  air-bubbles  out ;  the  joint  will  be  nearly  solid,  and 
has  been  proved  perfect.  The  parts  to  be  joined  should  be 
thinned  down  a  httle,  so  as  to  make  an  even  splice  ;  and  the 
vessel  containing  the  cement  kept,  tightly  corked,  in  a  cool 
place. 

Cement  for  Tracings. — Take  i  oz.  of  isinglass  glue,  and 
I  oz.  of  glue  made  of  parchment,  2  drachms  each  of  sugar- 
candy  and  gum  tragacanth.  Add  i  oz.  of  water,  and  boil 
together  till  mixed  ;  when  cold,  form  into  little  cakes.  When 
to  be  applied,  the  glue  may  be  wetted  on  a  bit  of  sponge,  and 
rubbed  on  the  edges  to  be  cemented  ;  they  will  readily  cohere 
on  pressure. 

Cement  for  Uniting  Wood  with  Metals,  Glass,  Stone, 
&C. — Dissolve  glue  in  boiling  water,  and  make  it  of  the  same 
consistence  as  cabinetmaker's  glue  \  then  add,  while  stirring, 
a  sufficient  quantity  of  wood  ashes  to  produce  a  varnish-like 
mixture.     While  hot,  the  surfaces  to  be  united  must  be  covered 


CEMENTS  AND  GLUES.  8i 

or  coated  with  this  glue  compound,  and  firmly  pressed  together, 
"When  cold,  the  joint  will  be  strong,  and  the  article  ready  for 
use. 

Chemical  Cement.— By  melting  together  2  lbs.  of  wax,  10 
lbs.  of  resin,  mixed  with  4  oz.  of  plaster  of  Paris,  and  2  lbs.  of 
red  ochre,  an  excellent  cement  can  be-  made  to  serve  for 
chemical  and  electrical  apparatus. 

Cement  for  Fixing  Metal,  Glass,  Porcelain,   &c. — The 

following  is  a  simple  and  useful  cement,  having  also  the 
additional  recommendation  of  cheapness.  Make  a  tolerably 
strong  solution  of  alum,  stir  into  it  plaster  of  Paris,  until  the 
liquid  becomes  of  the  consistency  of  cream,  and  use  while  in  a 
liquid  state. 

This  cement  may  be  used  for  fastening  brasses  on  lamps,  &c. 

Cementl  for  Mother-of-Pearl,  &c. — In  60  parts  of  water 
dissolve  4  parts  of  white  glue  and  2  parts  of  isinglass  ;  then 
strain  and  evaporate  until  its  volume  is  reduced  to  -^th  ;  add 
-jig-th  part  of  gum  mastic  dissolved  in  i  part  of  alcohol,  and  2 
parts  of  zinc.  When  required  for  use,  it  requires  to  be  warmed 
and  shaken. 

Glue  that  will  Eesist  the  Action  of  Water. — Boil  i  lb. 
of  common  glue  in  2  quarts  of  skimmed  milk. 

Cement  for  Glass  that  will  Eesist  Heat. — Equal  parts  of 
•wheat,  flour,  glass,  and  chalk,  finely  powdered  ;  to  this  mix- 
ture add  half  as  much  brick  dust,  and  a  little  scraped  hnt  in 
the  white  of  eggs. 

Cement  for  Aquaria. — Any  of  the  following  cements  may 
be  used  to  prevent  leakage  : — 

1.  I  pint  fine  white  sand,  i  pint  litharge,  |ds  of  a  gill  of 
finely-powdered  resin.  Mix  well,  and  keep  in  a  corked  bottle. 
When  used,  it  requires  to  be  mixed  with  boiled  oil  and  driers, 
until  of  the  consistency  of  putty.  Do  this  mixing  in  quanti- 
ties just  sufficient  for  each  piece  of  glass,  as  it  dries  ver)^ 
quickly. 

2.  Boiled  oil,  red  and  white  lead,  and  litharge  mixed  together, 
and  spread  on  a  flannel,  and  placed  on  the  joints. 

3.  2  oz.  benice  turpentine,  and  solution  of  glue  i  lb.  Boil 
these  together,  stirring  the  whole  time  until  perfectly  mixed. 

F 


82  CEMENTS  AND  GLUES. 

This  cement    sets  slowly,  and  the  joints  require    to  be  kept 
together  for  two  days. 

4.  Collins'  cement,  which  is  elastic,  waterproof,  and  harm- 
less, dries  very  quickly.  When  used,  it  should  be  cut  up  into 
small  pieces  about  the  size  of  a  pea,  and  laid  along  the  joint ;  a 
heated  wire  then  being  applied,  the  cement  will  run  into  a 
continuous  strip  along  the  joint. 

Fire  and  Water-Proof  Cements. — i.  Take  2  parts  of 
finely-sifted,  unoxidised  iron  filings,  mix  with  i  part  of  per- 
fectly dry  and  finely-powdered  loam,  and  knead  the  mixture 
with  strong  vinegar  until  a  perfectly  homogeneous, plastic  mass 
is  formed,  when  the  cement  is  ready  for  use.  It  must  be  made 
as  wanted,  for  it  quickly  hardens,  and,  once  set,  is  never  fit  for 
use  again. 

2.  A  very  excellent  cement  for  smaller  articles  is  made  thus  : 
— Soak  2  drachms  of  cut  isinglass  in  2  oz.  of  water  for 
twenty-four  hours  ;  boil  to  i  oz.,  add  spirit  of  wine  i  oz.,  and 
strain  through  linen.  Mix  this,  while  hot,  with  a  solution  of  i 
drachm  of  mastic,  in  i  oz.  of  spirit  of  wine,  and  triturate  with 
^  drachm  of  powdered  gum  ammoniac,  till  perfectly  homo- 
geneous. 

Postage-Stamp  Gum.— The  gum  used  for  stamps  is  what 
is  called  British  gum,  which  is  mgtde  from  starch  ;  its  proper 
name  is  dextrine  QaHioOio ;  it  is  usually  made  by  heating 
commercial  starch  suddenly  to  320°  ;  anhydrous  starch  requires 
a  temperature  of  400°,  and  maintaining  it  at  this  heat  for  some 
time.  The  .soluble  product  is  dextrine  or  British  gum,  or  the 
leiogomme  of  the  French.  Dextrine  may  be  prepared  on  a  large 
scale,  of  a  much  lighter  colour,  by  the  following  process  : — 
10  parts  starch  mixed  with  3  of  water,  containing  i- 150th 
of  its  weight  of  nitric  acid,  allowing  the  mixture  to  dry 
spontaneously,  and  then  spreading  it  upon  shelves  to  the  depth 
of  i^  in.,  and  heating  for  an  hour  or  hour  and  a  half  to 
above  240°. 

Cement  for  Hot-Water  Pipes. — Ram  on  to  the  flange  a  few 
strands  of  tarred  rope,  and  fill  up  with  iron  boring  cement,  and 
ram  in  well. 

Cement  for  Joining  Steam  Pipes. — Boiled  linseed  oil, 
litharge    and    whitelead,  mixed  up    to    a  proper    consistence, 


VARNISHES  AND  LACQUERS.  83    ' 

and  applied  to  each  side  of  a  piece  of  flannel,  linen,  or  even 
pasteboard  ;  and  then  placed  between  the  pieces  before  they 
are  brought  home,  as  it  is  called,  or  joined.  The  cement  is 
useful  in  joining  broken  stones,  seams  of  water  cisterns,  &c. 

Cement  for  Joining  Steam  Joints. — Sal  ammoniac,  2  oz.  ; 
sublimed  sulphur,  i  oz.  ;  fine  cast-iron  turnings,  i  lb.  ;  mix  in 
a  mortar,  and  keep  dry.  When  to  be  used,  mix  with  twenty 
times  its  quantity  of  clean  iron  turnings  or  filings,  and  triturate 
the  whofe  in  a  mortar.  Then  wet  with  water  until  of  a  con- 
venient consistence. 

Red  Putty  for  Steam  Joints. — Stiff  whitelead  worked  well 
in  redlead  powder. 

Durable  Cement. — Common  clay  well  dried  and  powdered, 
then  mixed  with  boiled  linseed  oil :  it  will  last  years.  Mix 
ground  whitelead  with  as  much  powdered  redlead  as  will 
make  it  the  consistency  of  putty.  Mix  equal  weights  of  red- 
lead  and  whitelead  with  boiled  linseed  oil  to  a  proper  con- 
sistence. These  three  cements  mend  stones  well,  however 
large. 

Liquid  Glue. — White  glue,  16  oz.  ;  dry  whitelead,  4  oz.  ; 
soft  water,  2  pints  ;  alcohol,  4  oz.  :  stir  together,  and  bottle 
while  hot. 

Varnishes. — In  accordance  with  the  nature  of  the  solvent, 
varnishes  are  called  spirit  varnishes,  turpentine  or  volatile  oil 
varnishes,  or  fat  oil  varnishes.  The  first  of  these,  whose 
solvent  is  sometimes  ether  or  chloroform,  but  more  commonly 
spirits  of  wine  or  wood  spirit,  dry  off  rapidly.  These  are  very 
thin  in  coat  when  dry,  and  are  best  suited  for  paper,  fans,  or 
any  very  fine  work  requiring  perfect  transparency  in  the 
varnishes.  Volatile  oil  varnishes,  in  which  the  solvents  are 
spirits  of  turpentine,  or  coal  naphtha,  or  the  like,  are  those 
mostly  employed  by  the  oil  painter.  What  is  called  "  French 
varnishing,"  so  much  employed  upon  the  wood  of  furniture,  &c., 
consists  in  the  apphcation  of  ahernate  films  of  lac  varnish 
and  of  linseed  oil,  with  constant  and  sufficient  friction  to 
polish  the  compound  film  of  spirito-fat  oil  varnish  as  soon  as  it 
has  become  thick  enough  to  afford  a  glossy  surface,  the  total 
thickness  being  exceedingly  small.  The  method  of  varnishing 
employed  by  the  carriage-builder  for  his  finest  work  is  the  very 


VARNISHES  AND  LACQUERS. 


opposite  of  this.  Over  his  last  coat  of  paint  he  lays  on  coat  after 
coat  of  copal  or  dammar  varnish,  until  he  has  got  a  consider- 
able thickness,  often  nearly  ^b-th  of  an  inch.  When  this 
to  its  full  depth  has  got  hard  and  perfectly  vitreous  in  the 
warmth  of  the  "  varnishing-room,"  the  whole  surface  is  literally 
ground  off  with  pumice-stone  and  water  until  a  perfect  form,  as 
to  contour,  and  a  perfect  superficies  have  been  procured,  when 
the  glossy  face  of  the  varnish  is  then  polished  by  putty  powder, 
chamois  skins,  the  hand,  &c.,  just  as  a  plate  of  looking-glass 
is  polished. 

Black  Japan  Varnish. — i.  Boiled  oil,  i  gallon;  amber, 
8  oz.;  asphaltum,  3  oz.;  oil  of  turpentine,  as  much  as  will 
reduce  it  to  the  thinness  required. 

2.  Take  pitch  50  lbs.,  dark  gum  amber  8  lbs.,  melt  this,  and 
add  linseed  oil  12  gallons.  Boil  this,  and  add  10  lbs.  more 
gum  amber,  previously  melted  and  boiled  with  2  gallons  of 
linseed  oil,  7  lbs.  each  of  litharge  and  redlead,  and  boil  for  two 
hours,  or  until  a  little  of  the  mass  can  be  rolled  into  pills  ;  then 
withdraw  the  fire  and  thin  the  varnish  as  required  for  use  with 
turpentine. 

Varnish  for  Coloured  Drawings. — Take  4  oz.  of  spirits 
of  turpentine,  and  mix  with  2  oz.  of  Canada  balsam.  Size 
the  picture  with  a  solution  of  isinglass  in  water.  When  this  is 
dry,  lay  on  the  varnish  with  a  camel's  hair  brush. 

Varnish  for  Paintings. — Take  mastic,  6  oz,  ;  pure  tur- 
pentine, I"  oz.;  camphor,  2  drachms  ;  spirits  of  turpentine, 
19  oz.;  add  first  the  camphor  to  the  turpentine.  The  mixture 
is  made  in  a  water-bath ;  when  the  solution  is  effected,  add 
the  mastic  and  the  spirits  of  turpentine  near  the  end  of  the 
operation  ;   filter  through  a  cotton  cloth. 

Varnish  for  Glass. — Dissolve  gum  adragant  in  the  white  of 
eggs,  beat  up  well,  and  lay  it  on  the  glass  with  a  soft  brush. 
The  gum  will  take  about  twenty-four  hours  to  dissolve. 

Aniline  Black  Varnish. — The  following  is  an  approved 
Parisian  varnish  : — In  a  litre  of  alcohol,  1 2  grammes  of  aniline 
blue,  3  grammes  of  fuchsine,  and  8  grammes  of  naphthaline 
yellow  are  dissolved.  The  whole  is  dissolved  by  agitation  in 
less  than  twelve  hours.      One    application  renders    an  object 


VARNISHES  AND  LACQUERS.  85 

ebony  black.       The    varnish  can  be  filtered,  and  will    never 
deposit  afterwards. 

Paper  Varnish. — Below  we  give  an  excellent  method  of 
varnishing  paper.  First  prepare  the  following  varnish  : — Pound 
very  fine  4  oz.  white  sealing-wax,  and  after  having  sifted  it 
through  a  lawn  sieve,  dissolve  it  in  2  oz.  of  alcohol.  To 
dissolve,  the  ingredients  must  be  put  into  a  large  bottle,  and 
be  shaken  frequently  during  the  space  of  forty-eight  hours. 
Give  your  work  two  coats  of  a  size  made  by  boiling  parchment 
cuttings  in  clear  water,  observing  to  do  it  quickly.  When 
dry,  apply  the  above  varnish. 

To  Varnish  Rarefied  Air  Balloons. — With  regard  to 
rarefied  air  machines,  first  soak  the  cloth  in  a  solution  of  sal 
ammoniac  and  common  size,  using  i  lb.  of  each  to  every 
gallon  of  water ;  and  when  the  cloth  is  quite  dry,  paint  it 
over  on  the  inside  with  some  earthy  colour,  and  strong  size  or 
glue  ;  when  this  paint  has  dried  perfectly,  it  will  then  be  proper 
to  cover  it  with  oily  varnish,  which  might  dry  before  it  could 
penetrate  quite  through  the  cloth.  Simple  drying  linseed  oil 
will  answer  the  purpose  as  well  as  any,  provided  it  be  not  very 
fluid. 

Copal  Varnish. — One  of  the  best  preparations  for  this 
varnish  is  the  following  : — Dissolve  i  oz.  of  camphor  in  i  quart 
of  alcohol,  put  it  in  a  circular  glass,  and  add  8  oz.  of  copal  in 
small  pieces  ;  set  it  in  a  sand  heat  until  it  is  dissolved,  so 
regulated  that  the  bubbles  may  be  counted  as  they  rise  from 
the  bottom,  and  continue  the  same  heat  until  the  solution  is 
completed.  Camphor  acts  more  powerfully  upon  copal  than 
any  substance  yet  tried.  If  copal  be  finely  powdered,  and 
mixed  with  a  small  quantity  of  camphor,  in  a  mortar,  the 
whole  soon  becomes  one  tough,  coherent  mass. 

Colourless  Varnish  with  Copal. — To  prepare  this  var- 
nish, which  can  be  applied  to  wood,  metals,  &c.,  the  copal 
must  be  picked  ;  each  piece  is  broken,  and  a  drop  of  rosemary 
oil  poured  on  it.  Those  pieces  which  on  contact  with  the  oil 
become  soft  are  the  ones  used.  The  pieces  being  selected, 
they  are  ground  and  passed  through  a  sieve,  being  reduced  to 
a  fine  powder.  It  is  then  placed  in  a  glass,  and  a  correspond- 
ing volume  of  rosemary  oil  poured  over  it ;  the  mixture  is  then 
stirred  for  a  few  minutes  until  it  is  transformed  into  a  thick 


86  VARNISHES  AND  LACQUERS. 

liquor.  It  is  then  left  to  rest  for  two  hours,  when  a  few  drops 
of  rectified  alcohol  is  added  and  intimately  mixed.  Repeat 
the  operation  until  the  varnish  is  of  a  sufficient  consistency ; 
leave  to  rest  for  a  few  days,  and  decant  and  clear. 

Varnish  for  Perforated  Zinc.-r-i  dwt.  of  Canada  balsam, 
thinned  with  spirits  of  turpentine  until  it  is  the  consistency  of 
milk.  Then  with  a  camel's  hair  flat  brush  sparingly  varnish 
the  perforated  zinc.  It  does  not  require  to  be  made  warm,  as 
articles  do  which  have  to  be  lacquered.  It  is  this  varnish  which 
is  usually  made  use  of  in  fixing  and  covering  the  silvered  parts 
of  clock  faces. 

Wood  Varnish  to  Resist  Boiling  Water. — Boil  3  lbs. 
of  linseed  oil  in  an  untinned  copper  vessel.  While  boiling, 
suspend  in  the  oil  a  bag  containing  6  oz.  of  minium  and  10  oz. 
litharge,  both  finely  powdered,  so  that  it  will  not  touch  the 
bottom  of  the  vessel.  When  the  oil  has  acquired  a  deep-brown 
colour,  take  out  the  bag  and  replace  it  by  one  containing  a 
small  piece  of  garlic.  Melt  2  lbs.  of  yellow  amber  with  4  oz. 
of  linseed  oil,  and  throw  into  the  vessel.  Let  the  whole  boil 
for  about  four  and  a  half  minutes,  stirring  well.  After  it  has 
rested  awhile,  decant  it ;  and  when  cold,  pour  it  into  stoppered 
bottles. 

The  wood  having  received  the  necessary  colour,  and  having 
been  properly  polished,  four  coats  of  the  above  should  be  laid 
on  with  a  fine  sponge. 

A  method  of  coating  wood  with  a  varnish  as  hard  as  stone 
has  been  recently  introduced  :  the  ingredients  are — 40  parts 
of  chalk,  40  of  resin,  4  of  linseed  oil,  to  be  melted  together  in 
an  iron  pot.  i  part  of  native  oxide  of  copper,  and  i  of  sulphuric 
acid,  are  then  to  be  added,  after  which  the  composition  is 
ready  for  use.  It  is  applied  hot  to  the  wood  with  a  brush,  in 
the  same  way  as  paint,  and  as  before  observed,  becomes 
exceedingly  hard  on  drying. 

Varnish  for  Wood  Patterns. — 3  oz.  of  shellac,  \\  oz.  of 
resin,  dissolved  in  a  pint  and  a  half  of  wood  naphtha. 

French  Polish. — Any  of  the  following  receipts  for  French 
polish  may  be  used: — i.  Shellac,  i  lb.  ;  naphtha,  2  lbs.  ; 
dragon's  blood,  3  oz.  2.  Shellac,  15  oz.  ;  powdered  mastic, 
\  oz.  :  sandarac,  \  oz,  ;  copal  varnish,  5  oz.  ;  methy- 
lated spirit,  2  lbs.      3.   Shellac,  22  oz.  ;   spirit  of  wine,  4  pints  ; 


VARNISHES  AND  LACQUERS.  87 

cod-liver  oil,  2  oz.  4.  Spirit  of  wine  or  naphtha,  i  pint ; 
gum,  \  oz.  ;  shellac,  3  oz.  ;  dissolve  with  a  gentle  heat,  and 
add  2  oz.  of  oil  of  sweet  almonds.  5.  Shellac,  i  oz.  ;  oxalic 
acid,  I  drachm  ;  naphtha,  4  oz.  ;  dissolve,  and  then  add  \  oz.  of 
linseed  oil.  6.  i  J  lb.  shellac  to  i  gallon  spirit  is  a  good  pro- 
portion ;  naphtha  should  be  used  only  for  coarse  work. 
Methylated  spirit  is  much  preferable.  No  better  polish  is 
made  than  that  with  shellac  alone,  but  in  finishing,  let  the 
work,  if  small,  and  can  be  conveniently  done,  be  warmed. 

Varnish  for  Violins. — The  varnish  most  used  for  violins  is 
what  is  called  a  "fat "  or  oil  varnish,  made  with  amber.  This 
is  the  most  insoluble  of  gum  resins,  and,  in  its  natural  state, 
soluble  only  in  chloroform.  It  contains  an  essential  oil,  oil  of 
amber,  and,  until  deprived  of  this  by  the  process  of  melting, 
cannot  be  mixed  or  dissolved  in  spirits  of  turpentine.  To  form 
it  into  a  varnish  for  violins,  melt  it  very  carefully  in  a  sand- 
bath.  A  small  iron  saucepan  half-filled  with  sand,  in  which  a 
small  thin  cup  is  embedded  to  contain  the  amber,  which  should 
be  coarsely  powdered,  will  answer  the  purpose.  If  black 
smoke  comes  from  the  melting  amber,  the  heat  is  too  great — 
the  amber  is  burning  ;  the  right  heat  must  be  found  by  trial, 
it  will  be  pretty  well  marked  by  the  smoke  or  vapour  being 
light-coloured  or  white.  This  indicates  the  evaporating  oil  of 
amber,  which  may  be  condensed  if  a  retort  and  receiver  is  used. 
The  vapour  has  a  very  powerful  penetrating  smell.  A  small 
quantity  of  amber  will  suffice,  say  i  drachm,  to  make  varnish 
for  two  or  three  violins.  The  amber,  when  sufficiently  melted, 
will,  when  cool,  be  of  a  dark-brown  colour,  and  in  small  brittle 
flakes.  In  this  state  put  it  into  a  small  bottle  with  camphine 
(the  best  spirit  of  turpentine  procurable),  sufficient  for  solution 
(about  four  times  the  bulk  of  the  prepared  amber).  Allow  the 
mixture  to  remain  a  day  or  two,  with  occasional  shaking  ;  then 
add  best  drying  linseed  oil,  equal  to  -^th  part  of  camphine. 
Size  your  violin,  and  get  the  grain  of  the  wood  thoroughly 
smooth,  and  apply  the  varnish  with  your  finger  on  a  warm 
sunny  day,  exposing  the  violin  to  the  sun  and  air.  A  number 
of  coats  will  be  required,  but  a  second  should  not  be  put  on 
until  the  first  is  dry.  Colouring-matter  may  be  rubbed  up  with 
a  palette  knife,  and  some  of  the  varnish,  but  there  is  great 
difficulty  in  laying  the  colour  on  smoothly. 


88  VA RNISHES  AND  LA  CQ  UERS. 

Friction  Polish. — A  good  polish  for  iron  or  steel  rotating 
in  the  lathe  is  made  of  fine  emery  and  olive,  sperm,  or  neat's 
foot  oil.     Apply  by  lead  or  wood  grinders,  screwed  together. 

Soft  Varnish. — For  a  good  soft  varnish,  take  linseed  oil, 
4  oz.  ;  and  J  oz.  each  of  gum  benzoin  and  white  wax.  Boil  to 
two-thirds. 

Dryers. — Grind  i  lb.  of  white  copperas,  i  lb.  sugar  of  lead, 
and  2  lbs,  whitelead  with  boiled  linseed  oil.  Boiled  or  drying 
oil  is  linseed  oil  mixed  with  powdered  litharge,  and  heated  till 
it  becomes  thick.  A  "  pale  "  drying  oil  is  obtained  by  mixing 
with  linseed  oil  sufficient  dry  sulphate  of  lead  to  form  a  milky 
liquid,  and  shaking  it  repeatedly  for  some  days,  letting  it  stand 
exposed  to  the  light.  When  it  has  become  quite  clear,  it  may 
be  poured  off  from  the  dregs.  The  sulphate  of  lead,  when 
washed  from  the  mucilage,  may  be  again  used  for  the  same 
purpose. 

Vehicle  for  Colour. — A  good  vehicle  for  colour  is  made  by 
boiling  shellac  and  borax  in  water.  This  solution  may  be 
used  as  a  varnish,  and,  mixed  with  lampblack,  forms  an  ink 
which  will  resist  almost  any  acid. 

Substitute  for  Brewer's  Pitch. — Coat  twice  the  inside  of 
a  barrel  with  a  solution  of  \  lb.  of  rosin,  2  oz.  of  shellac,  2  lbs.  of 
turpentine,  and  \  oz.  of  yellow  wax  in  i  quart  of  strong  alcohol. 
After  the  complete  drying  of  the  second  coat,  give  a  last  coat 
by  applying  a  solution  of  i  lb.  of  shellac  in  i  quart  of  strong 
alcohol.  This  varnish  will  perfectly  cover  up  the  pores,  and 
does  not  crack  off  or  impart  a  foreign  taste  to  the  beer. 

Lacquers. — Lacquers  are  used  upon  polished  metals  and 
wood,  to  impart  the  appearance  of  gold.  As  they  are  wanted 
of  different  depths  and  shades  of  colours,  it  is  best  to  keep  a 
concentrated  solution  of  each  colouring  ingredient  ready,  so 
that  it  may  at  any  time  be  added  to  produce  any  desired  tint. 
Lacquer  should  always  stand  till  it  is  quite  firm  before  it  is 
used. 

1.  Deep  Golden-coloured  Lacquer. — Seed  lac,  3  oz,  ;  tur- 
meric, I  oz.  ;  dragon's  blood,  ^  oz.  ;  alcohol,  i  pint.  Digest 
for  a  week,  frequently  shaking.      Decant  and  filter. 

2.  Gold-coloured  Lacq uer.^Ground  turmeric,    i  lb. ;   gam- 


VARNISHES  AND  LACQUERS.  89 

boge,  1 1"  oz.  ;  gum"  sandarac,  3|-  lbs.  ;  shellac,  |  lb.  (all  in 
powder);  rectified  spirits  of  wine,  2  gallons.  Dissolve,  strain, 
and  add  i  pint  of  turpentine  varnish. 

3.  Red-coloured  Lacquer. — Spanish  anatto,  3  lbs.  ;  dragon's 
blood,  I  lb.  ;  gum  sandarac,  3  J  lbs.  ;  rectified  spirits,  2  gallons  ; 
turpentine  varnish,  i  quart.      Dissolve  and  mix  as  the  last. 

4.  Pale  Brass-coloured  Lacquer. —  Gamboge,  cut  small,  i  oz.; 
cape  aloes,  ditto,  3  oz.  ;  pale  shellac,  i  lb.  ;  rectified  spirits, 
2  gallons.      Dissolve  and  mix  as  No.  2. 

5.  Seed  lac,  dragon's  blood,  anatto,  and  gamboge,  of  each 
\  lb.  ;  saffron,  i  oz.  ;  rectified  spirits  of  wine,  10  pints.  Dis- 
solve and  mix  as  No.  2, 

Excellent  lacquers  are  also  made  by  the  following  receipts  : — 

1.  Gold  Lacquer. — Put  into  a  clean  4-gallon  tin  i  lb.  ground 
turmeric,  \\  oz.  of  powdered  gamboge,  3|-  oz.  of  powdered 
gum  sandarac,  |  lb.  of  shellac,  and  2  gallons  of  spirits  of  wine. 
After  being  agitated,  dissolved,  and  strained,  add  i  pint  of 
turpentine  varnish,  well  mixed. 

2.  Red  Lacquer. — 2  gallons  of  spirits  of  wine,  i  lb.  of  dragon's 
blood,  3  lbs.  of  Spanish  anatto,  \\  lbs.  of  gum  sandarac, 
2  pints  of  turpentine.      Made  as  No.  i  lacquer. 

3.  Pale  Brass  Lacquer. — 2  gallons  of  spirits  of  wine,  3  oz.  of 
cape  aloes,  cut  small,  i  lb.  of  fine  pale  shellac,  i  oz.  of  gam- 
boge, cut  small,  no  turpentine  varnish.      Made  exactly  as  before. 

Those  who  make  lacquers  frequently  want  some  paler,  and 
some  darker,  and  sometimes  inclining  more  to  the  particular 
tint  of  certain  of  the  component  ingredients.  Therefore,  if 
a  4-0Z.  vial  of  a  strong  solution  of  each  ingredient  be  prepared, 
a  lacquer  of  any  tint  can  be  procured  at  any  time. 

4.  Pale  Tin  Lacquer. — Strongest  alcohol,  4  oz,  ;  powdered 
turmeric,  2  drachms  ;  hay  saffron,  i  scruple  ;  dragon's  blood 
in  powder,  2  scruples  ;  red  saunders,  \  scruple.  Infuse  this 
mixture  in  the  cold  for  forty-eight  hours,  pour  off  the  clear,  and 
strain  the  rest ;  then  add  powdered  shellac,  |-  oz.  ;  san- 
darac, I  drachm  ;  mastic,  i  drachm ;  Canada  balsam,  i 
drachm.  Dissolve  this  in  the  cold  by  frequent  agitation,  laying 
the  bottle  on  its  side,  to  present  a  greater  surface  to  the  alcohol. 
When  dissolved,  add  40  drops  of  spirits  of  turpentine. 

5.  Deep  Gold  Lacquer. — Strongest  alcohol,  4  oz.  ;  Spanish 
anatto,  8  grains  ;  powdered  turmeric,  2  drachms  ;  red 
saunders,  12  grains.      Infuse  and  add  shellac,  &c.,  as  to  the 


90  SOLDERS  AND  SOLDERING. 

pale  tin  lacquer  ;  and  when  dissolved,  add  30  drops  of  spirits 
of  turpentine. 

6.  Another  Gold  Lacquer. — Seed  lac,  6  oz.  ;  amber  gum, 
guttae,  2  oz.  each ;  extract  of  red  sandal-wood  in  water,  24 
grains  ;  dragon's  blood,  60  grains  ;  oriental  saffron,  36  grains  ; 
pounded  glass,  4  oz.  ;  pure  alcohol,  36  oz.  Grind  the  amber,  the 
seed  lac,  gum  guttas,  and  dragon's  blood  on  a  piece  of  por- 
phyry ;  then  mix  them  with  the  pounded  glass,  and  add  the 
alcohol,  after  forming  with  it  an  infusion  of  the  saffron  and  an 
extract  of  the  sandal-wood.  Then  grind  all  thoroughly.  The 
metal  articles  destined  to  be  covered  by  this  varnish  are  heated, 
and  such  small  articles  as  will  admit  of  it,  as  small  cases,  watch- 
keys,  &c,,  are  immersed  in  packets.  The  tint  of  the  varnish 
may  be  varied  by  modifying  the  doses  of  the  colouring  substances. 

Before  Lacquering  Brass  boil  it  in  a  solution  of  potash 
and  soda,  after  which  dip  them  in  aquafortis,  3  parts  water. 
Then  wash  them  in  two  different  waters,  and  rub  them  through 
sawdust.  Then  place  on  a  gas  stove.  When  warm,  brush  and 
put  the  lacquer  on.  After  this  operation  is  complete,  the  work 
is  put  back  on  the  stove  with  a  piece  of  brown  paper  over  it. 
You  can  burnish  or  pick  out,  as  you  please. 

Good  Lacquer  for  Brass. — Seed  lac,  6  oz.  ;  amber  or 
copal,  2  oz.  ;  best  alcohol,  4  gallons  ;  pulverised  glass,  4  oz.  ; 
dragon's  blood,  40  grains  ;  extract  of  red  sandal-wood,  obtained 
by  water,  30  grains. 

Pale  Lacquer  for  Tin  Plate. — Best  alcohol,  8  oz.  ; 
turmeric,  4  drachms  ;  hay  saffron,  2  scruples  ;  dragon's  blood, 
4  scruples ;  red  saunders,  i  scruple ;  shellac,  i  oz.  ;  gum 
sandarac,  2  drachms  ;  gum  mastic,  2  drachms  ;  Canada 
balsam,  2  drachms  ;  when  dissolved,  add  spirits  of  turpentine, 
80  drops.. 

Lacquer  for  Philosophical  Instruments. — Alcohol,  80 
oz.  ;  gum  gutta,  3  oz.  ;  gum  sandarac,  8  oz ;  gum  elemi, 
8  oz.  ;  dragon's  blood,  4  oz.  ;  seed  lac,  4  oz.  ;  terra  merita,  3 
oz.  ;   saffron,  8  grains  ;  pulverised  glass,  12  oz. 

Solders  and  Soldering. — Soft  Solders. — Tin  and  lead 
in  equal  parts.  Easier  of  fusion  still  is  tin,  lead,  and  bis- 
muth, in  equal  parts  ;  or  i  or  2  bismuth,  i  lead,  and  i  tin, 
easier   still.      For  soft   soldering  brass,  tin-foil  makes   a  fine 


SOLDERS  AND  SOLDERING.  91 

juncture,  applied  between  the  joints,  care  being  taken  to  avoid 
too  much  heat.  This  is  most  excellent  for  fine  brass-work. 
The  tin-foil  must  be  moistened  in  a  strong  solution  of  sal- 
ammoniac. 

Plumber's  Solder. —  i  part  bismuth,  5  parts  lead,  and 
3  parts  tin,  forms  a  compound  of  great  importance  in  the 
arts. 

Brass  Solder  for  Iron. — Melt  the  plates  of  brass  between  the 
pieces  that  are  to  be  joined.  When  the  work  is  very  fine,  the 
parts  to  be  brazed  should  be  covered  with  powdered  borax, 
melted  with  water,  so  that  it  may  mix  with  the  brass  powder 
which  is  added  to  it.  Expose  the  piece  to  a  clear  fire  in  such 
a  manner  that  it  shall  not  touch  the  coals,  and  let  it  remain 
until  the  brass  begins  to  run. 

Silver  Solder  for  Jewellers. — Take  20  dwt.  of  brass, 
2  dwt.  of  copper,  and  38  dwt.  of  fine  silver,  and  melt  them 
together. 

Silver  Solder  for  Plating.—  Take  \  oz.  of  pure  silver  and 
5  pennyweights  of  brass,  and  melt  them  together. 

Soldering  Steel  and  Iron  without  heat. — Take  \  oz 
of  thirid  acid,  \  oz.  of  spelter,  \  oz.  of  bismuth,  and  \  oz.  of  nitric 
acid.  Put  them  all  into  the  thirid  acid  ;  after  well  mixing, 
touch  each  part  required  to  be  soldered  with  the  mixture,  and 
put  them  together. 

Solder  for  Tinware. — An  excellent  solder  for  tinware 
can  be  made  from  the  lining  of  tea-chests. 

Soldering  for  Leaden  Gas- Pipes. — The  blowpipe  is  not 
absolutely  necessary,  as  the  flame  of  the  candle  gives  heat 
sufficient  for  the  purpose  by  itself  :  prepare  the  joint  in  the 
usual  way,  then  grease  and  sprinkle  on  a  little  pow'dered  rosin. 
Now  appLy  the  flame  of  the  candle,  and  touch  with  a  strip  of 
fine  solder  :  as  soon  as  the  joint  is  sufficiently  heated,  the 
solder  will  flow  easily.  One  candle  will  be  sufficient  for  the 
smaller  sizes  of  pipe  ;  but  by  using  two  or  more  candles, 
joints  may  be  made  in  this  way  up  to  1  in.  or  i;^  in.  The  solder 
must  be  fine,  such  as  tinners  use  ;  poured  out  in  thin  strips, 
and  cut  by  the  shears  \  in.  broad.  In  gasi-pipes  of  what  is 
called  composition  metal  the  blowpipe  is  absolutely  necessary ; 


92  METALS  AND  METAL-WORKING. 

and,  in  fact,  a  blowpipe  is  most  useful,  and  used  in  directing 
the  flame  round  the  pipe  or  to  a  required  spot,  and  keeping  up 
a  continuous  heat. 

Blowpipe  Joints  are  thus  made : — Slightly  taper  one  end  of 
the  pipe,  and  open  the  other  end  for  it  to  fit  into  ;  clean  the 
inside  of  the  opened  length,  and  the  outside  of  the  tapered  end. 
Grease  the  same  with  common  tallow,  and  sprinkle  a  little 
powdered  rosin  on  it.  Now  with  lo-in.  blowpipe  in  the  mouth, 
and  rushes  or  spirit  lamp  held  in  the  left  hand,  and  a  thin  strip 
of  soft  solder  in  the  right,  gently  heat  the  pipe  before  applying 
the  solder.  This  solder  should  be  composed  of  3  parts  fine 
tin,  to  2  of  lead.  A  small  portion  of  bismuth  wall  make  it  flow 
more  easily. 

Soldering,  Hard. — One  of  the  most  common  is  that  of 
silver  soldering ;  it  is  composed  of  silver  2  parts,  brass  i  part 
(common  pins  are  the  best).  The  silver  is  melted  first,  the 
brass  then  added  and  well  melted  together ;  it  is  then  milled 
to  the  thickness  of  stout  paper. 

The  work  that  requires  to  be  soldered  should  be  scraped 
clean  and  bound  together  with  iron  binding- wire. 

A  piece  of  lump  borax  is  next  rubbed  with  a  little  clean 
water  on  a  piece  of  slate  to  the  consistency  of  cream  :  the  work 
should  be  covered  with  this  by  means  of  a  small  pencil,  especially 
the  parts  to  be  soldered  ;  the  solder  is  then  cut  into  very  small 
pieces  and  laid  across  the  joint  with  the  pencil  also  ;  the  work 
is  then  put  on  a  piece  of  charcoal  or  bundle  of  iron  wires,  and 
gradually  heated  till  the  solder  melts  (by  means  of  the  blow- 
pipe and  gas).  For  rings,  a  piece  of  solder  is  passed  between 
the  join,  and  served  as  above  (be  careful  of  the  stones,  they 
must  not  be  made  red  hot).  Gold  is  generally  soldered  by 
gold  of  an  inferior  quality,  as  22  carat  soldered  with  18  carat, 
1 8  carat  with  1 6  carat,  &c.  After  soldering  the  binding-wire 
is  removed,  and  the  work  boiled  in  nitric  or  sulphuric  acid 
pickle  (i  part  acid,  10  parts  water),  and  finished  accordingly. 
It  requires  much  practice  to  become  master  of  the  blowpipe. 

Brass  Melting. — The  best  method  of  melting  brass  is  in 
a  plumbago  crucible.  The  best  furnaces  are  built  of  fire-brick, 
open  at  the  top,  with  an  opening  in  the  upper  part  of  the 
back,  connecting  the  furnace  with  the  chimney,  and  another 
larger  opening  in  the   front,  below  the  grate  bars.     A  good 


METALS  AND  ME  TAL-  WORKING.  93 

practical  furnace  may  be  made  12  in.  square  inside,  18  in. 
deep  to  grate,  1 2  in.  below  grate  for  cinders  and  air-passage, 
chimney  opening  4^  by  3,  and  3  in.  from  top  of  furnace. 
This  furnace  is  large  enough  for  a  No.  25  crucible,  which  will 
melt  about  50  lbs.  of  brass.  ' 

To    avoid   Air-holes    or   Flaws   in   Brass    Castings.— 

The  theory  of  their  formation  is  as  follows  : — Melted  metal  is 
more  bulky  than  cold  metal,  and  as  the  outside  of  castings  cool 
first,  it  follows  that  the  shrinking  must  take  place  within.  The 
so-called  air-holes  are  in  reality  not  air-holes  at  all,  but  cavities 
formed  by  the  shrinking  of  the  metal.  To  avoid  them,  endea- 
vour to  equalise  the  patterns  by  coring,  &c.  If  such  is  not  to 
be  done,  run  from  the  thickest  part  with  a  heavy  runner.  This 
process  will  tend  to  keep  all  in  a  fluid  state  until  the  outer 
portions  have  set,  and  so  fill  the  cavities  as  they  form. 

Bending  Brass  Tubes. — Brass  tubes  are  best  joined  by 
brazing  up  with  melted  brass.  Tubes  for  musical  instru- 
ments are  bent  by  first  filling  them  with  lead,  which,  as  soon 
as  they  have  been  brought  to  the  required  shape,  is  easily 
melted  out  again. 

Brass  Pickling  or  Brightening. — In  order  to  remove 
the  grease  and  dirt  that  may  have  accumulated  during  the 
process  of  fitting,  the  work  should  be  placed  in  a  red-hot 
muffle,  or  over  an  open  fire  ;  unless  it  be  soft  soldered,  when  of 
course  it  must  be  annealed  before  being  fitted.  If  that  be  the 
case,  or  if  the  work  have  ornamental  surfaces,  it  should  be 
boiled  in  potash  lye.  When  this  is  done,  immerse  it  in  a  bath 
composed  of  diluted  sulphuric  or  nitric  acid  in  the  proportions 
of  I  part  acid  to  3  of  water.  Allow  the  work  to  remain  in 
this  solutioTi  for  from  one  to  two  hours,  according  to  the 
strength  of  the  acid  ;  then  rinse  with  water,  and  scour  with 
sand,  using  a  common  scrubbing-brush  ;  then  wash  well.  To 
make  the  pickling-bath,  dissolve  2  parts  of  zinc  in  6  parts 
of  nitric  acid  of  36°  Baume,  in  a  porcelain  vessel,  then  add 
to  the  mixture  1 6  parts  of  nitric  acid  and  1 6  parts  of  sulphuric 
acid.  Boil  this  liquid,  and  while  boiling,  plunge  the  work 
into  it  for  about  half  a  minute,  until  the  nitrous  vapour 
ceasing,  the  surface  becomes  uniform.  Then  rinse  it  well 
in  clear  water,  to  remove  the  acid.     Should  the  work  have 


94  METALS  AND  METAL-WOK  KING. 

assumed  a  greyish-yellow  tint,  this  may  be  removed  by 
immersing  the  work  for  a  short  time  in  nitric  acid.  It 
should  then  be  rinsed  in  a  weak  solution  of  potash,  and 
covered  with  beech  or  boxwood  sawdust,  and  afterwards  rubbed 
until  quite  dry ;  after  this  it  should  be  lacquered,  to  prevent  the 
action  of  the  atmosphere ;  and  if  a  green  tint  be  required,  a 
little  turmeric  mixed  with  the  lacquer  will  give  it.  By  immers- 
ing the  work  in  a  solution  of  white  arsenic  in  hydrochloric 
acid,  a  dark-greyish  tint  is  obtained. 

Coating  Copper. — To  coat  with  Antimony. — Dissolve  2  oz. 
of  butter  of  antimony  in  i  quart  of  spirits  of  wine,  and  add 
hydrochloric  acid  until  the  solution  is  clear.  Into  this  solution 
put  the  object  to  be  coated,  previously  well  cleaned  and  polished. 
In  the  course  of  three-quarters  of  an  hour  a  solid  and  brilHant 
covering  of  antimony  is  deposited.  Cast  iron  may  be  coated 
with  copper  by  placing  it  in  an  alkaline  solution  of  chloride  of 
copper,  and  then  covered  with  antimony  by  the  above  process. 

Coating  Copper. — The  best  way  to  coat  copper  with  platinum 
for  a  battery  is  to  bend  a  sheet  of  zinc  to  enclose  a  porous  cell, 
and  connect  the  zinc  without  the  cell  in  a  suitable  vessel  with 
the  copper  in  the  cell,  then  fill  both  vessels  with  sulphuric  acid 
I,  water  10,  and  drop  a  little  solution  of  bichloride  of  platinum 
into  the  porous  cell  :  it  will  be  instantly  thrown  down  on  the 
copper  as  black  powder. 

German  Silver,  to  polish. — An  excellent  powder  for 
cleaning  German  silver  and  other  bright  metals  can  be  made  in 
the  following  manner.  Take  \  lb.  of  peroxide  of  iron  (crocus). 
Put  it  into  a  wash-basin  and  pour  on  water,  stirring  with  the 
hand.  While  the  water  is  in  slow  motion,  pour  off  the  mixture, 
leaving  the  grit  at  the  bottom  ;  repeat  this  operation,  and  then 
put  it  at  one  side  until  the  crocus  has  settled  at  the  bottom. 
When  it  has  done  so,  drain  off  the  water,  dry  the  powder,  and 
keep  in  a  bottle  or  canister. 

If  the  work  to  be  cleaned  is  very  dirty,  mix  a  little  of  the 
powder  with  oil  ;  rub  it  on  with  the  fingers,  and  polish  in  the 
usual  manner.  If  only  slightly  tarnished,  put  a  little  of  the 
powder  on  a  piece  of  wash  leather,  and  polish  well,  taking  care 
that  the  leather  be  free  from  dust. 

Hardness  of  Silver. — Goldsmiths  often  complain  of  the 
hardness  of  silver,  which  is  sometimes  very  difficult  to  carve, 


METALS  AND  METAL-WORKING.  95 

and  presents  a  dead  grey  cut.  These  properties  are  generally- 
attributed  to  the  presence  of  a  foreign  metal ;  but  M.  Mathey, 
assayer  at  Locla,  has  shown  that  in  this  silver  there  is  neither 
tin,  lead,  nor  any  other  injurious  metal.  He  considers  this 
property  to  be  due  solely  to  the  high  temperature  at  which  sil- 
ver is  cast.  By  letting  the  crucible  cool  till  a  slight  solid  crust 
is  formed  on  the  surface  of  the  fused  metal,  and  casting  at  this 
moment,  a  soft  silver  with  a  brilhant  cut  is  obtained. 

Tarnished  Plate,  to  clean. — Silver  or  plated  objects  may 
be  cleaned,  if  tarnished,  by  dipping  them,  when  they  are  small, 
into  a  moderately  concentrated  solution  of  cyanide  of  potassium, 
and  when  they  are  large,  by  brushing  the  solution  over  the 
tarnished  portions,  then  washing  well  with  distilled  water,  and 
afterwards  drying  with  a  linen  cloth. 

Silver  and  Galena,  to  separate. — If  sulphuret  of  silver 
is  melted  with  chloride  of  lead,  a  decomposition  takes  place, 
and  sulphuret  of  lead  and  chloride  of  silver  is  formed.  If, 
therefore,  galena,  which  consists  of  sulphuret  of  lead  with  some 
sulphuret  of  silver,  is  melted  together  with  chloride  of  lead,  the 
silver  is  extracted  from  the  galena,  and  lead  takes  its  place. 
On  this  principle  depends  the  new  process,  which  is  carried 
out  as  follows  : — The  galena  is  mixed  with  i  per  cent,  chloride 
of  lead  and  10  per  cent,  common  salt.  If  it  contains  much 
silver,  a  greater  quantity  of  chloride  of  lead  is  added.  The 
mixture  is  melted,  and  the  chloride  of  silver  formed  by  these 
rneans,  together  with  the  salt,  floats  on  the  top,  and  can  easily 
be  separated  from  the  pure  galena.  The  mixture  of  chloride 
of  silver  and  common  salt  is  afterwards  melted  together  with 
lime  and  charcoal,  or  treated  in  some  other  suitable  manner, 
whereby  the  silver  and  the  lead  contained  in  the  remaining 
chloride  of  lead  is  reduced.  The  mixture  of  silver  and  lead 
thus  obtained  is  afterwards  separated  in  the  ordinary  manner. 

Artificial  Gold. — Take  16  parts  virgin  platina,  7  parts 
copper,  I  part  zinc.  Place  the  whole  in  a  crucible,  covered 
with  powdered  charcoal,  and  melt  until  formed  into  one  mass. 
For  a  brazing  solder,  take  1 2  lbs.  of  copper,  and  1 1  lbs.  of  zinc  ; 
flux  with  powdered  brimstone. 

Gold,  to  Dissolve. — 2  parts  hydrochloric  acid  and  i  nitric 
acid  (aqua  regia)  will   dissolve  gold.     Apply   gentle  heat  to 


96  METALS  AND  METAL-WORKING. 

accelerate  chemical  action.  To  colour  gold,  make  up  2  dwt. 
of  sulphate  of  copper,  4  dwt.  12  gr.  French  verdigris,  4  dwt. 
sal  ammoniac,  4  dwt.  nitrate  of  potassa,  acetic  acid  about  i  oz. 
Reduce  the  sulphate  of  copper,  sal  ammoniac,  and  nitrate  of 
potassa  to  a  powder,  add  the  verdigris,  then  pour  in  the  acid 
little  by  little  ;  dip  the  article  in  by  any  convenient  means, 
and  heat  on  a  piece  of  copper  till  black.  When  cold,  place 
in  tolerably  strong  sulphuric  acid  pickle,  rinse  well  in  warm 
water,  to  which  a  little  potash  has  been  added. 

Case  Hardening. — For  occasional  case  hardening  upon  a 
small  scale  a  very  good  box  may  be  made  by  welding  a  plug 
into  the  end  of  a  piece  of  wrought-iron  pipe,  and  using  a  loose 
plug  for  the  opposite  end;  the  loose  plug  will,  of  course,  require 
to  be  fastened  into  its  -place  with  an  iron  pin  passing  through  it 
and  the  pipe  ;  it  will  require  to  be  luted  with  clay  or  loam  ; 
part  of  the  plug  must  project  out  of  the  pipe  for  the  convenience 
of  pulling  it  out. 

Composition  used  in  Welding  Cast  Steel. — Borax,  10; 
sal  ammoniac,  2  ;  flowers  of  sulphur,  i  part ;  grind  or  pound 
them  roughly  together  ;  then  fuse  them  in  a  metal  pot  over  a 
clear  fire,  taking  care  to  continue  the  heat  until  all  scum  has 
disappeared  from  the  surface.  When  the  liquid  appears  clear, 
the  composition  is  ready  to  be  poured  out  to  cool  and  concrete  ; 
being  ground  to  a  fine  powder,  it  is  ready  for  use.  To  use 
this  composition,  the  steel  to  be  welded  is  raised  to  a  heat 
which  may  be  expressed  by  "  bright  yellow  \ "  it  is  then  dipped 
into  the  welding  powder,  and  again  placed  in  the  fire  until  it 
attains  the  same  degree  of  heat  as  before  ;  it  is  then  ready  to  be 
placed  under  the  hammer. 

Inlaying  witli  Mother  -  of  -  Pearl. —  Having  procured 
mother-of-pearl  of  the  required  shades,  and  properly  cut  into 
thin  scales,  fasten  the  pieces  on  the  article  to  be  inlaid  with 
cement,  according  to  whatever  design  you  may  have  chosen. 
Then  cover  the  rest  of  the  surface  with  successive  coats  of 
Japan  varnish,  baking  after  each  coat,  until  it  is  flush  with  the 
surface  of  the  pearl. 

White  Metal  is  an  alloy  of  10  of  tin,  i  of  copper,  and 
I  of  antimony.  This  is  a  capital  composition,  running 
very  smoothly;  when  kept  from  heating  it  will  last  longer  than 
brass,  and  with  a  good  deal  less  friction.      It  was  used  a  great 


METALS  AND  METAL-WORKING.  97 

deal  for  lining  the  working-parts  of  eccentrics,  also  for  the  stern 
tube  bearings  of  screw  propellers,  before  the  introduction  of 
the  use  of  timber  for  this  purpose.  It  is  generally  cast  inside 
of  cast-iron  steps,  merely  as  a  liner,  the  low  temperature  at 
which  it  melts  rendering  it  dangerous  to  make  the  whole  step  of 
this  composition,  except  in  cases  where  the  entire  bearing  is 
enclosed  in  a  bath  of  oil  or  water.  It  is  a  fact  which  has  been 
practically  proved,  though  not  generally  known,  that  for  ex- 
tremely high  speeds,  such  as  fan-shaft,  saw-mills,  &c.,  nothing 
beats  cast  iron  on  cast  iron.  For  locomotive-work,  or  first- 
class  engine  or  machine  work  of  any  description,  nothing  is 
better  than  what  is  known  by  the  name  of  gun  metal,  which  is 
an  alloy  of  i  of  tin,  i  of  zinc,  and  8  of  copper. 

Polished  Steel,  to  Preserve. — You  can  preserve  polished 
steel  from  rust  by  mixing  some  oil  with  caoutchouc ;  melt  in 
a  close  vessel,  stirring  to  prevent  burning.  A  high  temperature 
will  be  required.  This  will  form  a  perfect  air-proof  skin  over 
the  surface,  which  may  very  easily  be  removed  by  brushing 
with  warm  oil  of  turpentine. 

Glazers  for  Polishing  Metal. — There  are  two  kinds  of 
glazers  for  polishing  metal,  dry  and  soft.  The  dry  glazer  is 
for  doing  coarse  work,  and  is  constructed  as  follows  : — An 
outer  coating  of  wood  of  a  uniform  thickness,  say  2  inches,  is 
secured  by  means  of  screws  to  a  cast-iron  wheel ;  the  wood 
must  be  turned  after  it  is  fastened.  It  is  then  surrounded  by  a 
leather  strap,  which  must  be  thoroughly  soaked  in  water  to  make 
it  pliable.  The  strap  is  fastened  in  this  manner  :  a  coating  of 
glue  is  placed  on  the  wood,  one  end  of  the  strap  is  nailed  to 
the  glazer,  the  strap  is  then  pressed  round  the  circumference  by 
means  of  a  round  iron  bar,  and  at  intervals  of  3  or  4  inches  a 
row  of  nails  is  driven  through  the  strap — these  nails  are  made 
expressly  for  the  purpose,  they  are  round,  with  square  heads 
and  polished  points,  to  keep  them  from  rusting  and  make  them 
easily  drawn.  The  strap  having  been  all  nicely  secured,  the 
glazer  is  hung  up  to  dry,  a  process  which  generally  requires  a 
week,  in  consequence  of  the  soaked  state  of  the  leather.  When 
the  glazer  is  dry  enough,  the  leather  is  coated  with  glue,  the 
emery  is  placed  on  a  paper  on  the  floor,  a  spindle  having  been 
attached  to  the  glazer.  A  man  is  placed  at  either  end  of  the 
spindle,  who  rolls  the  glazer  over  the  emery  backwards  and 

G 


98  METALS  AND  METAL-WORKING. 

forwards,  lifting  it  up  and  letting  it  down,  in  order  to  make  the 
emery  fast,  and  to  cause  as  much  to  adhere  as  possible  j  it  is 
then  hung  up  to  dry,  and  it  is  fit  for  use  in  a  few  hours. 

The  soft  glazer  is  made  all  of  wood,  except  that  it  is  secured 
by  iron  bands.  The  emery  in  this  case  is  mixed  with  tallow 
and  formed  into  cakes.  When  the  emery  is  to  be  applied,  the 
workman  takes  a  tool  something  like  a  hoe  with  a  hammer 
shank,  and  along  the  cutting  edge  is  a  row  of  teeth  ;  he  then 
strikes  the  glazer  all  round,  leaving  the  teeth-marks  as  thick 
as  possible;  he  then  takes  a  piece  of  cake  emery  and  tallow, 
and  presses  it  all  round  the  glazer  ;  it  is  fit  for  use  immediately 
after.  No  amateur  should  work  on  a  wood  glazer  ;  because  if 
an  edge  catches  the  wood,  the  consequences  will  be  serious. 

Breaking  Weight   of  Cast-iron   Rectangular  Beams. — 

The  breaking  weight  of  rectangular  beams  may  be  correctly 
ascertained  from  data  given  by  Dr  Fairbairn.  His  experi- 
ments on  43  samples  of  hot  and  cold  blast  iron  bars,  each 

1  in.  square,  and  supported  on  bearers  placed  4  ft.  6  in.  apart, 
gave,  as  the  average  breaking  weight,  45274  lbs.  ;  hence,  for 
any  other  bar  or  beam  of  similar  section  : — Breaking  weight 

4-5 (^  dz  s 

W  =  where  b  =  breadth,  d  —  depth,  and  /  =  length  of 

b 
beam,  s  —  the  co-efficient  above  given — viz.,  45274'^ lbs.      If 
the  beam  be  fixed  at  both  ends,  it  will  sustain  one-half  as  much 
again  as  when  supported. 

Preservation  of  Polished  Steel  Surfaces.  —  Polished 
surfaces  of  steel  and  iron  may  be  preserved  from  rusting  by 
exposure  to  water,  if  whilst  so  exposed  they  are  covered  over 
with  a  mixture  of  lime  and  oil. 

Taking  Buckles  out  of  Sheet  Iron. — The  tools  generally 
used  are  as  follows  : — A  large  cast-iron  plate,  about  2  ft. 
diameter  and  2  in.  thick,  with  the  face  a  little  convex  (it  is 
called  a  setter),  and  a  hammer  of  about  4  lbs.  or  5  lbs.,  about 

2  in.  flat  face.  Hammer  the  sheet  iron  wherever  it  is  tight,  or 
where  it  does  not  buckle,  so  as  to  stretch  it  equal  to  where  the 
buckles  are ;  by  so  doing  you  will  bring  it  flat,  but  this  requires 
patience  and  practice.  A  large  plate  of  iron,  as  above  stated, 
is  the  best  to  set  your  work  out  on  ;    because  you  can  more 


METALS  AND  ME  TAL-  WORKING.  99 

easily  see  the  extent  of  the  buckle,  and  where  the  tie  is  located 
that  requires  to  be  hammered.  The  process  can  be  made 
much  easier  by  passing  the  sheet  iron  through  a  pair  of  rollers 
such  as  are  used  by  tin  and  iron  plate  workers. 

Preservation  of  Sulphate  of  Iron. — Mix  4  parts  of  pure 
crystallised  sulphate  of  iron,  and  an  equal  quantity  of  finely- 
powdered  gum  arable,  with  distilled  water,  and  evaporate 
the  solution  in  a  water-bath,  at  a  low  heat,  till  it  has  a  suffi- 
cient consistency  to  be  poured  out  on  plates  of  glass.  When 
it  has  been  poured  out  in  this  way,  and  allowed  to  dry  at  a 
temperature  of  30°  Cent,  in  the  dark,  it  may  be  cut  up  into 
lozenges,  which  can  be  kept  for  any  length  of  time  in  a  coloured 
stoppered  bottle. 

Composition  of  Mixed  Metals.  Pewter. —  r.  100  parts 
of  tin,  1 7  parts  of  antimony  ;  the  French  add  a  little  copper. 
2.  12  lbs.  of  tin,  I  lb.  of  antimony,  4  oz.  of  copper.  3.  7  lbs. 
of  tin,  I  lb.  of  lead,  6  oz.  copper,  2  oz.  zinc.  Melt  the  copper 
first. 

White  Metal. — 2  lbs.  of  antimony,  8  oz.  of  brass,  and  10 
oz.  of  tin. 

Mosaic  Mixture. — Equal  parts  of  tin,  bismuth,  and  mercury, 
forms  a  metal  used  for  various  ornamental  purposes. 

Silvery-Looking  Metal. — A  ver>'  fine  silvery-looking  metal 
is  made  from  100  parts  tin,  8  parts  antimony,  i  part  bismuth, 
and  4  parts  copper. 

German  Titanium. — 2  drachms  of  copper,  i  oz.  of  antimony, 
and  1 2  oz.  of  tin. 

Spanish  Titanium. — 8  oz.  of  scrap  iron  or  steel,  i  lb.  of 
antimony,  and  3  oz.  of  nitre.  The  iron  or  steel  must  be  heated 
to  whiteness,  and  the  antimony  and  nitre  added  in  small  portions. 
2  oz.  of  this  compound  are  sufficient  to  harden  i  lb.  of  tin. 

Columbia  Metal. — 4J  lbs.  of  tin,  J  lb.  of  bismuth,  1  lb.  of 
antimony,  and  J  lb.  of  lead  ;  or,  100  lbs.  of  tin,  8  lbs.  of  anti- 
mony, I  lb.  of  bismuth,  and  4  lbs.  of  copper.  This  alloy  is  used 
for  making  teapots,  and  other  vessels  which  imitate  silver. 

Type-Metal  of  the  French  letter-founders  :  -f  of  lead  and 
i  of  regulus  of  antimony.  The  letter-founders  of  Berlin  use 
II  lbs.  of  antimony,  25  lbs.  of  lead,  and  5  lbs.  of  iron.      Many 


METALS  AND  METAL-WORKING. 


add  tin,  copper,  and  brass  ;  while  some  make  their  types  from 
3  parts  of  lead  to  i  of  antimony. 

German  Silver. — i.  25  parts  nickel,  20  parts  zinc,  and 
60  parts  copper.  If  for  casting,  add  3  parts  of  lead.  2.  16 
parts  copper,  8  parts  zinc,  and  3^^  parts  nickel.  3.  8  parts  of 
copper,  3 J  parts  zinc,  and  2  parts  of  nickel.  4.  28  parts 
copper,  13  parts  zinc,  and  ']\  parts  nickel.  5.  Copper,  8 
parts  ;  zinc,  3  J  parts  ;  nickel,  3  parts.  This  last  is  a  very 
beautiful  compound.  It  has  the  appearance  of  silver  a  little 
below  standard.  By  some  persons  it  is  even  preferred  to  the 
more  expensive  compound.  Manufacturers  are  strongly 
recommended  not  to  use  a  metal  inferior  to  this. 

Speculum  Metal. — i.  Copper,  32  parts;  tin,  14  parts; 
arsenic,  2  parts.  A  very  good  metal.  2.  Copper,  32  parts  ; 
tin,  1 3I  parts;  arsenic,  imparts.  3.  Copper,  32  parts;  tin, 
15  parts  ;  arsenic,  2  parts.  4.  Copper,  32  parts  ;  tin,  15  parts  ; 
brass,  i  part ;  silver,  i  part ;  arsenic,  i  part.  5.  Copper,  6 
parts  ;  tin,  2  parts  ;  arsenic,  i  part.  Sir  Isaac  Newton's 
mixture.  It  is  very  yellow  when  polished.  6.  Copper,  3 
parts  ;  tin,  \\  parts.  Compact,  and  whiter  than  the  last. 
7.  Brass,  6  parts  ;  tin,  i  part.  Compact,  but  too  yellow.  8. 
2  parts  of  6th  composition,  and  i  part  of  7th.  Much  too 
yellow  when  polished.  6,  7,  and  8,  are  experiments  by 
Professor  Molyneux,  F.R.S.  9.  Copper,  32  parts  ;  tin,  2 
parts  ;  arsenic,  i  part.  A  pretty  good  metal,  but  polishes  too 
yellow. 

Mercury,  to  Extract.— Make  a  solution  of  sulphate  of  mer- 
cury by  dissolving  it  in  a  solution  of  common  salt.  Add  to  this 
about  one  and  a  half  or  twice  its  bulk  a  solution  of  protochlo- 
ride  of  tin  (price  3d.  per  oz.)  You  will  get  a  white  precipitate, 
which  will  afterwards  turn  grey.  This  is  metallic  mercury.  To 
collect  it,  let  the  precipitate  settle,  and  pour  off  the  liquid  :  add 
dilute  hydrochloric  acid  (equal  parts  of  acid  and  water)  to  the 
precipitate,  and  boil.  The  mercury  will  gradually  collect  into 
globules. 

To  Prevent  Sand  sticking  to  Articles  when  Moulded.— 
Take  a  little  finely-powdered  charcoal,  in  a  fine  muslin  bag, 
and  shake  it  on  the  face  of  the  flask  of  sand  after  moulding 
patterns,  and  before  putting  the  top  flask  on,  and  when  well 
dusted  with  the  charcoal,  it  will  prevent  them  from  sticking. 


METALS  AND  METAL-WORKING. 


lOI 


923 

Iron,  cast,  i  part  in 

901 

719 

Lead,  pure,       ,, 

349 

...     584 

Platinum,           ,, 

..       1131 

...    581 

Silver,                , , 

524 

...     T248 

Tin,  pure,           ,, 

403 

682 

Tin,  impure,      ,, 

500 

846 

Zinc,                   ,, 

322 

Shrinking  of  Castings. — For  shrinkage  of  castings,  the 
pattern-maker's  rule  should  be,  for  cast  iron,  ^th  of  an  inch 
longer  per  lineal  foot ;  brass,  yg-ths  ditto  ;  lead,  Jth  ditto  ; 
tin,  -L^h  ditto  ;  zinc,  y^hs  ditto.  The  following  is  the  Hnear 
expansion  by  heat  from  30°  to  212°  of — 

Antimony,  i  part  in 

Bismuth,  , , 

Brass,  , , 

Copper,  ,, 

Flint  glass,        ,, 

Gold, 

Iron,  wrought,  ,, 

The  Amateur's  Smelting  Furnace. — A  simple  smelting 
furnace  for  brass,  &c.,  is  made  thus  : — 

The  large  vessel  No.  i  is  filled  with  sand,  to  prevent 
radiation  of  heat.  The 
small  crucible  stands  on 
a  grate.  i.  A  large 
tin  vessel ;  2.  a  large 
pot  or  crucible  ;  3. 
a  small  crucible ;  4. 
coke,  or  charcoal  ;  5. 
a  double  blast  bel- 
lows. 

Tinning. — First  cleanse  the  articles  to  be  tinned  by  placing 
them  in  warm  water,  mixed  with  a  little  oil  of  vitriol.  After 
washing  the  articles  in  clean  water,  dip  them  in  a  solution  of 
sal  ammoniac,  and  let  them  dry.  When  they  are  thoroughly 
dried,  place  them  in  a  shallow  pan,  the  bottom  of  which  is  full 
of  holes.  When  the  tin  is  melted,  sprinkle  a  little  sal  am- 
moniac over  the  surface,  and  dip  the  pan  containing  the 
articles  into  it.  When  the  smoke  has  cleared  away,  take  them 
out,  shake  them  over  the  pot,  and  sprinkle  a  little  sal  ammoniac 
over  them  ;   then  plunge  them  into  cold  water. 

Bisulphide  of  Tin. — Kletinsky  .dissolves  4  parts  of  salt  of 
tin  in  20  parts  of  water,  previously  mixed  with  2  parts 
of  strong  hydrochloric,  or  i  part  of  strong  sulphuric  acid. 
This  solution  is  heated  nearly  to  boiling,  and  then  saturated 
with  sulphuric  acid  gas.  The  following  reaction  takes  place  : — 
3Sna  +  2HO  +  SO3,  HO  +  5S02=  SnS2+  2(Sn02,  2SO3)  +  3H 


STEAM  ENGINE. 


CI.  The  yellow  sulphide  of  tin  is  collected  on  a  filter,  washed 
and  dried,  and  the  filtrate  may  be  distilled  to  recover  the 
hydrochloric  acid,  sulphate  of  tin  remaining  in  the  retort.  If 
the  dried  sulphide  of  tin  is  sublimed  at  a  red  heat,  access  of 
air  being  prevented,  beautiful  mosaic  gold  is  obtained  in  large 
shining  scales,  and  spangles  of  a  brilliancy  that  is  never  seen 
with  the  old  way  of  making  the  gold. 

Oxychloride  of  Zinc  may  be  prepared  by  dissolving 
granulated  zinc  in  hydrochloric  acid,  and  evaporating  when  a 
semi-solid  hydrated  mass  is  obtained  (butter  of  zinc).  The 
oxychloride  is  prepared  by  strongly  heating  this  mass  in  a 
porcelain  crucible. 

Working  Poor  Ores  of  Lead. — The  operation  on  lead  ores, 
which  contain  too  little  lead  and  too  much  earthy  matter  to  be 
smelted  profitably,  scientific  smelters  treat  with  muriatic  acid, 
with  heat,  upon  plates  of  stone  or  lead,  by  which  the  galena  is 
completely  converted,  if  the  ore  has  been  properly  prepared, 
into  chloride  of  lead.  The  mass  is  then  lixiviated  in  tubs  with 
double  bottoms,  holding  each  15  or  20  cwt.,  with  boiling  water 
to  extract  the  chloride  of  lead,  which  crystallises  out  in  great 
part  on  cooling,  the  mother  liquid  being  again  heated  to  boil- 
ing, and  used  over  again  continually.  The  deposited  chloride 
of  lead  is  reduced  to  the  metalUc  state  by  zinc,  forming  a 
spongy  lead,  which  may  be  either  melted  down  or  used  for 

making  whitelead, 
&c.  Some  iron 
having  been  thrown 
down  from  the  chlo- 
ride of  zinc  solution 
by  chloride  of  lime, 
the  zinc  must  be 
precipitated  by  lime 
as  pure  white  oxide 
of  zinc,  suitable  for 
pigmentary  pur- 
poses. 

Rotary  Engine. 

—  The      following 
sketch    and    expla- 
nation shows  the  principle  of  a  simple  Rotary  Engine  : — 


STEAM  ENGINE. 


103 


AA,   cylinder;    B,  piston;     C,  slide;     DD,  slide  box;    E, 

tiaust  port ;    F,  steam  port ;    G,  shaft. 

It  will  be  seen  that  the  piston  works  the  slide. 


Steam  Governors. — The  "  pendulum  ball "  contrivance  is 
probably  about  the  best  to  employ  as  a  regulator,  and  about  the 
worst  to  use — as  it  is  ordinarily  used — as  a  governor  of  machine 
speed.  The  following  invention  simply  embodies  a  plan  for 
employing  the  "  centrifugal  principle  "  in  the  way  for  which  it 
is  fitted,  instead  of  (as 
at  present  in  "  Watt's 
Governor")  the  mode 
for  which  it  is  especially 
unfit. 

The  apparatus  will 
be  easily  understood 
from  the  skeleton  dia- 
grams subjoined. 

Fig.  I.  A  is  a  box 
containing  a  train  of 
clockwork,  kept  going 
by  a  spring  or  weight, 
and  regulated  by  the 
conical  pendulum  B. 
The  works  are  wound 
up  every  morning  when 
the  engine  starts,  and 
thus  a  rotative  move- 
ment is  given  to  the 
wheel  C  throughout 
the  working  day,  which 
for  all  practical  pur- 
poses may  be  regarded 
as  invariable. 

In  fig.  2,  A  and  B 
are  two  circular  discs, 
shown  edgewise.  One 
face  of  each,  the  inner 
one,  is  flat.  On  the  other,  a  wheel  or  pulley  is  fixed,  by  which 
rotative  motion  is  communicated.  The  discs  revolve  "freely  and 
independently  on  fixed  axles.     One  of  these  discs,  A,  receives 


I04 


STEAM  ENGINE. 


its  rotation  by  a  strap  from  wheel  C  in  fig.  i,  and  therefore 
revolves  at  a  regular  rate.  Disc  B  in  like  manner  receives 
rotation  from  the  engine.  The  discs  are  so  fixed  that  thin  flat 
surfaces  revolve  in  parallel  planes,  but  in  opposite  directions. 
Through  the  fixed  axles  central  holes  are  drilled  to  receive  the 
spindle  of  the  "  governor,"  show^n  in  fig.  3,  where  A  is  a  spindle 
carrying  an  arm  B,  which  is  crowned  by  a  wheel  C,  revolving 
freely  on  its  centre.  The  length  of  the  arm  B  is  rather  less 
than  the  radius  of  the  discs  A  and  B  in  fig.  2  ;  and  the  diameter 
of  the  wheel  C  is  just  equal  to  the  distance  between  those 
discs.  All  these  dimensions,  as  well  as  the  velocity  of  rotation 
of  the  discs,  are  merely  matters  of  convenience. 

When  put  together,  the  ends  of  the  spindles  pass  through 
the  holes  in  the  fixed  axles,  and  play  freely  in  them.     The  arm  B 

projects  between  the 
^'^'  3-  discs  and  the  wheel 

C,  which  traverses 
round  near  their  out- 
ward edge,  and  is 
■  pretty  tightly  clipped 
by  them.  Its  rim  is 
belted  by  a  ring  of 
vulcanite,  or  other 
elastic  material,  so 
as  to  establish  agood 
bite.  One  end  of 
the  spindle  projects 
beyond  the  frame- 
^^  work,  and  carries  at 
its  extremity  an  end- 
less screw,  which 
works  into  the  teeth 
of  a  quadrant  D, 
connected  with,  and 
The  wheel  arrangement  is  shown 


I 


Fig.  4. 

the  throttle-valve. 


governmg 
in  fig.  4. 

The  action  of  the  instrument  is  very  simple.  So  long  as  the 
"  engine ''  disc  keeps  time  with  the  "  chronometer "  disc,  its 
"  governor "  wheel  C  will  simply  revolve  on  its  axis,  keeping 
the  spindle,  and  therefore  the  throttle -valve,  fixtures  in  their 
existing  position.     When  any  change  of  power  or  load  occurs. 


STEAM  ENGINE.  105 

and  the  engine  disc  begins  to  gain  or  lose,  the  "  governor  " 
wheel  at  once  begins  to  traverse  round  the  circle,  carrying  with 
it  the  spindle,  and  thus  acting  on  the  throttle-valve  until  a  new 
point  is  reached,  when  the  disc  velocities  are  again  equal;  and 
there  it  remains  until  new  conditions  supervene  requiring  fresh 
adjustments. 

By  this  means  the  engine  disc  can  never  vary  in  velocity 
from  the  chronometer  disc  for  more  than  a  few  seconds  at  a 
time,  while  the  process  of  adjustment  can  be  made  as  prompt 
and  dehcate  as  any  practical  necessities  may  require. 

Preventing  Incrustation  in  Boilers. — Mr  William  Irwin's 
invention  of  "  an  improved  compound  for  preventing  incrus- 
tation in  boilers,"  consists  in  the  mixing  with  the  water  in  a 
steam  boiler  a  compound  composed  of  the  following  ingredients, 
which,  by  preference,  are  mixed  together  in  the  following  pro- 
portions : — 

French  ochre |  lb. 

Oxford  ochre |  „ 

Brown  ochre f  „ 

Yellow  ochre |  ,, 

Vandyke  brown \  „ 

Spanish  brown  \  „ 

Purple  brown \  ., 

Ground  umber  |  „ 

Ground  ochre %  „ 

6  lbs. 

The  above  proportions  mixed  in  a  gallon  of  water,  and  put  into 
a  boiler  17  by  5  feet,  will  prevent  incrustation. 

Another  plan  is  to  introduce  a  small  quantity  of  chloride  of 
ammonium,  when  the  lime  which  forms  the  incrustation  will 
be  held  in  solution,  and  the  boiler  cannot  foul.  The  process 
is  equally  apphcable  to  fresh  or  salt  water.  This  will  effect  a 
saving  of  time,  heat,  and  fuel,  and,  more  than  all,  will  prevent 
one  of  the  principal  causes  of  explosions,  for  it  has  been  proved 
that,  in  most  instances,  the  foulness  of  the  boiler  has  been  the 
principal  cause  of  accident. 

Much  of  the  "  fur  "  in  boilers  depends  on  the  chemical  com- 
position of  the  water  used.  Sometimes  a  pound  of  common 
soda,  introduced  daily,  has  been  found  to  prevent  incrustation. 
This  for  driving  a  20  horse-power  engine.     The  deposit  is  in 


io6 


STEAM  ENGINE. 


the  state  of  powder.     Two  months  is  too  long  to  work  a  boiler 
without  cleaning,  except  in  rare  cases.     To  introduce  the  soda, 

have  a  small  cistern 
connected  with  the 
pump,  dissolve  in 
the  cistern,  and  then 
turn  on  your  tap. 

Blast  Engine. — 
In  the  following, 
the  swan-neck  rod 
should  be  made  of 
two  flat,  tapering 
bars.  In  the  sketch 
the  crank  is  repre- 
sented as  working 
6-feet  stroke,  and 
the  cylinder  working 
8-feet  stroke. 

Self -Acting  Boiler  Feeder. — The  figme  is  a  section  of  the 
apparatus.  The  water  from  a  cistern  enters  the  cylindrical 
reservoir  A  through  the  pipe  E,  closed  by  a  valve  B  opening 
upwards.      The  water  passes  into  the  boiler  through  the  pipe 

H,  closed  at  top  by  the  valve 
C  opening  downwards,  and 
closed  by  a  slight  spring. 

D  is  a  small  steam-pipe 
reaching  to  the  top  of  the 
reservoir,  and  having  a  3-way 
cock  where  shown.  The 
action  is  as  follows  :  —  On 
turning  the  3-way  cock  a 
communication  is  opened  be- 
tween the  cylinder  and  the 
outer  air ;  the  water  then 
enters  through  the  valve  B, 
and  fills  the  reservoir,  ulti- 
mately escaping  through  the  lateral  opening  in  the  3-way  cock. 
This  shows  the  reservoir  is  full.  On  now  turning  the  cock,  the 
lateral  passage  is  closed,  and  the  direct  communication  opened 
from  the   boiler  through  the   steam-pipe  D.      Equilibrium  of 


STEAM  ENGINE. 


107 


pressure  being  thus  established,  the  water  descends  through 
the  valve  C  and  pipe  H  into  the  bottom  of  the  boiler.  On 
again  reversing  the  cock  the  steam  escapes,  and  the  water 
enters  as  before. 

The  only  thing  to  be  done,  therefore,  is  to  turn  the  small 
cock  at  certain  intervals,  and  this  may  be  arranged  by  letting 
the  water  that  overflows  through  it  when  the  reservoir  is  full 
fall  into  a  receiver  so  arranged  as  to  tilt  over  when  full,  and  in 
tilting  over  turn  the  3-way  cock.  The  whole  would  thus  be- 
come entirely  self-acting. 


//  !  /  ■ 


A 


Engine  Governor. — To  make  a  governor  that  will  work 
correctly  and  show  its  speed,  mark  a  diagram  of  the  gover- 
nor,   showing    the  , 
centre    lines    only,                                        j 
when  in  its  proper 
working      position, 
viz.,  with  the  balls 
half  expanded.      If 
the    centre    line   of 
the  long  arm  be  ex- 
panded until  it  cuts 
the    centre    line   of 
the  spindle,  we  are 
able  to  measure  by 
a    scale,     on     the 
rule,    the    distance 
from  the  horizontal 
plane  of  the  balls  up 

to  the  point  in  the  | 

spindle  where  it  is  I 

cut  by  the  extended  I 

centre    hne    of  the 

arm ;  this  distance  is  the  vertical  height,  on  the 
which  depends  the  speed  of  the  governor.  The 
is —  187-5 

V =revs.  per  min. 

vertical  height  in  inches. 
This  gives  the  correct  speed  of  the  governor,  and  that  of  the 
engine  being  also  known,  before  the  required  size  of  the  wheels 
can  be  at  once  determined  upon. 


length   of 
rule    now 


lo8 


STEAM  ENGINE. 


Expansive  Governor  for  Steam  Engines,  &c.— It  fre- 
quently happens  in  many  manufacturing  operations  that  great 
variations  occur  in  the  work  which  the  engine  has  to  perform, 
and  in  all  cases  it  is  desirable  that  the  steam  should  be  used 
in  the  most  economical  manner.  With  the  use  of  the  ordinary 
throttle-valve  this  desirable  result  is  not  effected,  inasmuch  as 
the  retardation  is  caused  by  expansion  of  steam  before  admis- 
sion into  the  cylinder,  thus  losing  the  full  benefit  of  the  high 
pressure  stored  in  the  boiler  at  so 
much  risk.  In  order,  therefore,  to 
economise  in  this  respect  to  the  fullest 
extent,  the  steam  should  be  admitted 
to  the  cylinder  at  full  pressure,  and  the 
required  diminution  of  speed  effected 
by  a  proportionate  duration  of  the 
admission.  Such  a  variable  "  cut  off" 
is  produced  by  the  invention  we  now 
describe. 

Fig.  I  (the  bottom  of  which  is  the 
top  of  the  slide-valve  case  of  a  hori- 
zontal engine)  has  cast  with  it  the 
small  upright  cylinder,  closed  at  top, 
communicating  with  the  valve- case. 
The  upper  half  of  this  has  an  opening 
extending  about  half-way  round,  which 
is  shown  as  fig.  2.  Over  this,  and 
fitting  with  proper  ease,  is  another 
cylinder,  open  at  both  ends,  and  to  a 
cross-bar  at  top  is  fixed  the  rod  pro- 
ceeding upwards,  and  working  with 
the  bent  arms  of  the  governor.  At 
the  lower  half  is  a  cavity,  as  seen  in 
fig.  3.  Over  these  is  bolted  down  the 
cylindrical  steam-case,  provided  at  the 
side  with  steam-pipe  and  at  top  with  stuffing-box,  and  also  with 
support  for  the  bevil-wheel  actuating  the  governor.  The  revo- 
lutions of  this  wheel  being  made,  by  suitable  means,  to  corre- 
spond with  those  of  the  main  shaft,  and  proper  adjusting 
weights  placed  upon  the  small  shelf  provided  on  the  rod,  going 
through  the  stuffing-box,  the  effect  will  be  that,  as  the  centri- 
fugal force  depresses  the  said  rod,  so  will  the  openings  before 


STEAM  ENGINE.  109 


described  correspond  for  a  shorter  time,  and  the  speed  be 
regulated  as  desired.  The  effect  will  be  better  understood  by- 
referring  to  figs.  2  and  3,  where,  supposing  fig.  3  passed  across 
fig.  2,  in  the  direction  of  the  arrow,  represents  the  steam  on 
during  the  whole  stroke,  then  by  depressing  fig.  3,  and  passing 
it  across  as  before,  the  inclined  sides  are  brought  nearer  together, 
and  hence  the  "  cut  off"  takes  place  sooner.  The  lower  part 
of  fig.  I  is  in  section. 

The  Giffard  Injector  consists  of  three  cones,  A,  B,  and  C, 
B  is  the  combining  cone,  A  the  steam  cone,  and  C  the  receiv- 
ing cone.  The  steam  cone  can  be  moved  nearer  to  or  further 
from  the  combining  cone,  which  is  fixed  with  its  small  end  at 
a  short  distance  from  the  receiving  cone  C,  and  the  supply  of 
steam  can  be  regulated  by  the  rod  D,  worked  by  the  hand- 
wheel  k.  F  is  the  steam-pipe  opening  into  the  steam  cone 
above ;  g  is  the  water-supply  pipe  opening  into  cone  B.  H  is 
the  overflow-pipe  opening  into  an  annular  space  00,  surround- 
ing the  ends  of  the  cones  B  and  C,  finally  I  is  the  valve  open- 
ing into  the  boiler. 

The  action  is  as  follows  : — The  steam  rushes  through  pipe 
F  and  cone  A.  Now  take,  for  example,  the  case  of  a  boiler 
working  at  a  pressure  of  60  lbs.  per  square  inch  from  a  vacuum. 

A  cubic  foot  of  steam  at  the  atmospheric  pressure  will  weigh 
•047  lbs.,  therefore  the  weight  of  a  cubic  foot  of  60-lb.  steam 

60 
will  be  equal  to  —  x  "047  —  '188  lbs.  ;    also  the  weight  of  a 

15 
cubic  foot  of  water  is  62*4  lbs.      Now  the  velocity  of  issue  of  a 
fluid  under  pressure  is  equal  to  the  velocity  of  a  body  falling  from 
a  height  equal  to  the  height  to  which  a  column  of  the  fluid  would 
be  raised  by  the  pressure  in  question,  which  for  60-lb.  steam 


^60x144 


will  =  8  s] =  8  ^44800  =1712  feet  per  second.  Also  for 

•188  /60  X  144 


the  water  velocity  will  —  8  V =8  V 1 38-4  =  94  feet  per 

62-4 
second  nearly.      Now,  suppose   i   cubic  foot  of  steam  coming 
out  of  the  steam  cone  with  a  velocity  of  1 7 1 2  feet  per  second 
to  be  condensed  between  A  and  B,  it  would  form  about  four 
cubic  inches  of  water,  which  would  retain  the  velocity  of  the 


STEAM  ENGINE, 


steam  ;  and  as  this  is  rather  more  than  1 8  times  greater  than 
the  velocity  of  the  water  issuing  direct  from  the  boiler,  if  it  is 
mixed  with  about  1 6  times  its  bulk  of  water,  it  would  still  have 
a  velocity  rather  greater  than  94  feet  per  second,  so  it  would 
easily  open  the  valve  and  enter  the  boiler. 

Now  this  is  exactly  what  happens  in  the  injector.  Steam 
being  turned  on,  rushes  through  the  cones  A  and  B,  and 
escapes  at  the  overflow-pipe  H  ;  but  by  the  well-known  prin- 
ciples of  hydrodynamics,  it  induces  an  upward  current  of  water 

in  the  pipe  g  :  and 
as  soon  as  the  water 
reaches  the  cone  A, 
it  will  begin  to  con- 
dense   the     steam, 
and,    by    the    prin- 
ciples    already    ex- 
plained, if  the  bulk 
of    the    condensed 
steam  and  water  be  not  greater  than  about  1 7  times  the  bulk 
of  the  condensed  steam,  it  will  open  the  valve  T  and  enter  the 
boiler. 

If  the  supply  of  water  be  too  great,  and  the  velocity  thereby 
too  much  reduced,  it  will  rush  out  of  the  overflow-pipe  H 
instead  of  entering  the  boiler,  and  thereby  give  warning  to  the 
engineman  to  reduce  the  supply  of  water  by  moving  the  cone 
A  nearer  to  the  cone  B,  by  means  of  the  handle  E,  until  the 
water  just  ceases  to  drip  from  the  pipe  H.  If  more  water  be 
wanted  for  the  boiler,  the  pointed  rod  P  is  drawn  further  back 
to  admit  a  larger  quantity  of  steam,  and  the  cone  A  also  drawn 
back  till  a  slight  drip  comes  from  the  pipe  H,  when  the  injector 
will  be  working  to  its  greatest  effect.  It  is  evident  that  the 
quantity  of  feed-water  must  in  all  cases  be  sufficient  to  condense 
the  steam,  and  that  the  water  must  not  be  heated  to  more  than 
about  110°  Fahr.,  or  it  will  not  condense  fast  enough — .or  rather, 
the  quantity  required  will  be  too  great  for  the  steam  to  take 
into  the  boiler  with  it. 


Huxley's  Internal  Tappet  Pump  or  Steam  Engine. — As 

a  pump  this  will  be  found  specially  useful  in  deep  wells,  where 
frequently  much  inconvenience,  loss  of  time,  and  expense  arises 
from  the  defective  action  of  the  ordinary  valves,  also  necessi- 


STEAM  ENGINE. 


tating  the  descent  of  some  one  down  to  the  pump.  Here  we 
have  a  lift  and  force  pump,  of  double  action,  with  the  requisite 
changes  effected  by  a  tappet  piston  in  place  of  valves,  whose 
action  is  as  certain  as  the  revolution  of  a  crank  and  fly-wheel, 
the  necessary  appendage  to  the  piston-rod,  &c.  Fig.  i  is  the 
ordinary  cylinder  and  piston,  the  cover,  however,  having  a  long 
neck  to  the  stuffing-box  in  order  to  allow  of  the  movement  of 
the  tappet,  which  is  fastened  to 
the  piston-rod,  and  may  be  seen 
just  under  the  stuffing-box.  At 
the  side,  near  the  top  of  cylinder, 
are  three  ports,  as  usual ;  but  the 
ports  are  altered  in  arrangement, 
as  may  be  seen.  The  exit  port 
b  also  communicates  with  the  top 
of  piston,  through  a  circular  pas- 
sage made  in  the  tappet  piston 
before  referred  to,  and  surround- 
ing the  piston-rod.  The  action 
is  as  follows  : — The  piston  having 
ascended  to  the  hmit  allowed  by 
the  crank,  has  pushed  the  tappet 
piston  to  near  the  top  of  cylinder, 
and  is  ready  for  descent.  Supply 
port  a  is  in  communication  with 
top  of  piston,  causing  it  to  de- 
scend ;  exit  port  b  communicates 
with  port  c  through  a  cavity, 
which  is  seen  on  the  side  of  the 
tappet  piston,  and  thence  descends 
a  passage  and  opening  c  to  bottom 
of  piston.  The  piston  having  next 
arrived  at  bottom  of  cylinder,  the 
tappet  has  just  pushed  against  a 
cross-bar  provided  at  the  bottom 
of  tappet  piston,  and  its  position 

is  seen  in  fig.  2,  where  exit  port  b  communicates  through  the 
passage  described  in  tappet  piston  to  the  top  of  piston,  and 
supply  pipe  and  port  a  with  port  c  leading  to  bottom  of  piston, 
and  thus  proceeds  the  up-stroke,  and  produces  the  arrangements 
before  described  ready  for  another  down-stroke. 


1 1 2  STEAM  ENGINE, 


Power  of  Engines. — It  is  frequently  asked,  What  is  the 
power  of  an  engine  of  such-and-such  dimensions  ?  The  ques- 
tion will  be  answered  by  a  glance  at  the  following  rules,  which, 
amongst  many  others,  are  used  for  ascertaining  the  horse- 
power, will  explain  the  vague  and  uncertain  methods  we  have 
of  solving  such  a  problem.  In  Chambers's  "  Mechanics,"  the 
rule  for  non-condensing  engines  is,  Multiply  the  area  of  piston 
in  inches  by  the  pressure  per  square  inch  in  cylinder,  less  15 
lbs.  for  the  pressure  of  the  atmosphere  on  waste-steam  pipe. 
Then,  by  the  velocity  of  the  piston  in  feet  per  minute,  divide 
t>y  33,000,  and  ^  of  the  quotient  is  the  effective  power. 
Templeton's  rule  for  high  pressure  is,  Multiply  the  area  of 
piston  in  square  inches  by  the  average  force  of  steam  in  lbs., 
and  by  the  velocity  of  the  piston  in  feet  per  minute.  Divide 
by  33,000,  and  -^^5-  of  the  quotient  is  the  effective  power. 
Bourne  gives  the  following  rule  for  high  pressure  : — Square  the 
diameter  of  the  cylinder  in  inches,  multiply  by  the  pressure  of 
the  steam  in  the  cylinder  per  square  inch,  less  ij  lb.,  and  by 
the  piston's  velocity  in  feet  per  minute.  Divide  by  42,017  : 
the  quotient  is  the  effective  power.  The  first-mentioned  rule 
is  merely  given  by  way  of  illustration,  as  the  pressure  of  the 
atmosphere  is  not  generally  taken  into  account,  engines  of  this 
principle  being  supposed  to  work  in  a  medium.  The  rules  for 
ascertaining  the  nominal  power  are  equally  fallacious.  For 
condensing  engines  Bourne  gives  the  same  rule  as  for  non- 
condensing,  considering  that  the  deduction  of  a  i|^  lb.  is  rela- 
tively much  smaller  where  the  pressure  is  high,  than  where  it 
does  not  much  exceed  the  pressure  of  the  atmosphere.  Lard- 
ner  gives  the  following  rule  : — When  the  pressure  in  the 
cylinder  does  not  exceed  the  atmosphere  more  than  4  lbs.  or 
5  lbs.,  with  a  good  vacuum,  and  an  average  of  200  feet  per 
minute  for  the  velocity  of  the  piston,  square  the  diameter 
of  the  piston,  and  divide  by  28  :  the  quotient  is  the  horse- 
power. The  Admiralty  rule  is.  Square  the  diameter  of  the 
cylinder  in  inches,  and  multiply  by  the  speed  of  the  piston  in 
feet  per  minute.  Divide  by  6000  :  the  quotient  is  the  horse- 
power. 

Safety- Valves. — Many  and  various  are  the  plans  that  have 
been  adopted  and  suggested  for  producing  perfect  safety-valves 
for  steam  engines.     Without  an  effective  and  reliable  safety- 


STEAM  ENGINE.  1 1 3 


valve,  the  use  of  a  steam  boiler  must  be  constantly  attended 
with  the  most  imminent  danger.  Whatever  care  may  be  be- 
stowed by  the  manufacturer  on  the  construction  of  the  safety- 
valve,  it  may  be  rendered  nugatory  by  the  ignorance  or  temerity 
of  the  person  in  charge  of  the  engine,  since  he  may  overload 
the  valve,  and  thus  create  a  pressure  within  the  boiler  which  it 
was  not  constructed  to  endure,  and  which  it  may  not  be  capable 
of  bearing.  The  evil  may,  indeed,  be  prevented  by  the  use  of 
two  safety-valves,  one  of  which  is  beyond  the  power  of  the 
engineman.  But  ingenuity  has  devised  a  still  more  simple 
remedy ;  one  that  not  only  prevents  the  production  of  steam 
at  too  high  a  pressure,  but  which  actually  causes  every  attempt 
to  produce  it  to  be  accompanied  by  a  reduction  of  pressure, 
and  thus  removes  all  temptation  to  tamper  with  the  valve.  The 
new  form  of  safety-valve  differs  little  from  the  ordinary  kind, 
and  is  extremely  simple.  In  the  ordinary  kind  the  fulcrum  of 
the  lever  is  absolutely  immovable,  in  the  new  kind  it  is  fixed  ; 
in  ordinary  circumstances,  being  kept  down  by  a  spiral  spring. 
But  attempting  to  overload  the  valve  brings  the  lever  down  on 
a  stud,  which  is  at  the  side  of  the  valve  most  remote  from  the 
fulcrum,  and  which  comes  into  action  as  a  new  fulcrum  by 
supporting  the  lever,  changing  the  latter  from  the  third  to  the 
first  order.  The  former  fulcrum  yields  to  the  additional  weight, 
the  spiral  spring  being  compressed,  and  is  raised  up,  the  safety- 
valve  being  at  the  same  time  opened,  or  allowed  to  open  ;  and 
thus  the  steam  is  permitted  to  escape,  though  at  a  pressure  too 
small  to  raise  the  valve  when  weighted  as  it  should  be.  In  its 
normal  state,  the  fulcrum  of  the  lever  is  at  one  end,  the  weight 
at  the  other,  and  the  power — that  is,  the  tendency  of  the 
safety-valve  to  rise — between  the  fulcrum  and  weight.  When 
the  valve  is  overloaded,  the  weight — that  is,  the  resistance  of 
the  spiral  spring —  is  at  one  end,  the  power — that  is,  the  weight 
with  which  the  lever  is  loaded — is  at  the  other,  and  the  ful- 
crum— that  is,  the  stud  on  which  the  lever  has  been  brought 
down  by  the  overloading — is  between  the  power  and  weight, 
the  effect  of  the  latter  being  aided  by  the  tendency  of  the  steam 
to  raise  the  valve.  A  notice  of  some  of  the  most  recent,  there- 
fore, cannot  but  be  interesting  to  mechanicians  and  engineers. 
First,  we  have 

Mr  Swann^s  Patent. — In   this    case,    the   apparatus    is    so 
arranged  that  undue  weight  apphed  to  the  lever  of  the  valve,  in 

H 


114 


STEAM  ENGINE. 


place  of  allowing  an  increase  of  pressure  in  the  boiler,  will 
cause  the  steam  to  blow  off  at  any  pressure  to  which  the  appa- 
ratus may  be  set.  In  place  of  arranging  the  valve  lever  to 
turn  on  a  fixed  centre  as  usual,  the  centre  or  axis  is  arranged 
in  such  a  manner  that  it  is  kept  down  only  by  a  spring  or 

weight,  which  yields 
when  undue  pres- 
sure is  applied  at 
the  other  end  of  the 
lever ;  the  outer 
arm  of  the  lever 
then  descends  a 
short  distance  till 
.  it  comes  against  a 
fulcrum  arranged 
for  it  between  the 
valve  and  the 
weight,  and  then 
the  undue  weight 
applied  to  the  lever 
aids  in  taking  pres- 
sure from  the  valve. 
The  inner  end  of 
the  lever,  with  its 
centre  or  axis,  is 
cased  in  so  that  it 
cannot  be  tampered 
with.  The  same 
arrangement  is  ap- 
plicable where  an 
adjustable  spring  is 
applied  to  the  outer  end  of  the  valve  rod  in  place  of  a  sliding 
weight. 

Fig.  I  is  a  side  view,  fig.  2  a  plan,  and  fig.  3  is  a  vertical 
section  of  a  safety-valve  constructed  according  to  this  inven- 
tion. 

a  a\s  2^  casting  secured  by  bolts  to  the  top  of  the  steam 
chest ;  <5  is  a  bushing  of  brass  fitted  into  it  to  form  the  valve 
seat ;  c  is  the  valve,  held  down  by  the  weight  lever  d^  which 
-turns  at  one  end  of  the  pin,  <?,  and  at  the  other  receives  the 
isliding  weighty,  and  by  sliding  this  weight  on  the  lever  </,  the 


STEAM  ENGINE. 


"5 


pressure  on  the  valve  may  be  varied  as  desired,  g  is  the  ful- 
crum to  which  the  lever  d  is  jointed  by  the  pin  e^  and  this 
fulcrum  is  made  so  as  to  yield  when  a  heavy  pressure  is  put 
upon  it.  Its  stem,  g^^  drops  into  a  socket  bored  to  fit  it  in  the 
casting  a,  and  in  a  space  within  this  casting  the  stem,  ^', 
receives  the  spiral 
spring  h,  which  is 
retained  by  the  nut  i 
on  the  stem,  so  that, 
as  will  be  seen,  by 
screwing  up  the  nut 
/,  the  fulcrum  g  may 
be  held  down  in  its 
socket  with  any  de- 
sired force.  A  con- 
venient way  of  .ad- 
justing the  spring  h 
is  to  place  a  suitable 
weight,/,  at  the  end 
of  the  lever,  and  to 
screw  up  the  spring 
/  until  its  tension  is 
just  sufficient  to  hold 
down  the  fulcrum  g; 
k  \s  z.  stud  or  stop 
fixed  in  the  casting 
a,  in  such  a  position 
that,  as  soon  as  the  [^ 
-fulcrum^commences 

to  yield  in  consequence  of  an  excessive  weight  being  applied  to 
the  lever  d,  the  said  lever  may  come  down  on  to  the  stud, 
which  then  acts  as  a  new  fulcrum,  and  the  excessive  weight 
applied  then  assists  the  pressure  of  the  steam  in  lifting  the 
valve ;  /  is  a  cover  with  openings  in  it  for  the  passage  of  the 
lever  d,  and  for  the  escape  of  the  steam  ;  it  is  secured  by 
screws  or  otherwise  to  the  casting  a,  so  that  the  valve  may 
not  be  tampered  with ;  ;;z  is  a  screw  plug,  which  closes 
the  recess  in  the  casting  a,  in  which  the  spiral  spring  is  con- 
tained. 

In  connection  with  safety-valves  arranged  according  to  this 
invention,   apparatus  may   be   applied   to    indicate  when    the 


ii6 


STEAM  ENGINE. 


FIC4. 


water  in  the  boiler  is  deficient  by  causing  the  steam  to  escape 
from  the  valve.  Fig.  4  shows,  partly  in  section,  apparatus  for 
this  purpose  ;  ;2  is  a  bushing  screwed  into  the  top  of  the  boiler, 

and  I?  is  a  plug  passing 
^  !»  freely    through    it ;     a 

valve,  <9^,  is  formed  at 
its  lower  end,  and  this, 
resting  against  a  face  at 
the  lower  end  of  the 
bushing,  prevents  any 
escape  of  steam ;  p  is 
a  spiral  spring,  which 
tends  constantly  to  draw 
the  valve  0^  up  to  its 
seat ;  ^  is  a  chain  con- 
necting the  upper  end 
of  the  plug  0  with  the 
outer  end  of  the  weight 
lever  d  of  the  valve  ;  r 
represents  a  heavy  float 
connected  by  a  chain 
with  the  lower  end  of 
the  plug  <9,  and  which 
should  rest  on  the  sur- 
face of  the  water  in  the 
boiler ;  when,  however, 
the  water  falls  too  low, 
this  float,  being  unsup- 
ported, its  weight  draws 
down  the  plug  <?,  and 
by  the  chain  q  the 
weight  of  the  float  is 
transmitted  to  the  lever 
d^  and  this  additional 
weight  causes  the  pressure  on  the  safety-valve  to  be  relieved, 
as  already  explained. 

What  is  claimed  is  the  arranging  the  parts  of  a  safety-valve, 
as  hereinbefore  described,  and  especially  the  combined  applica- 
tion to  safety-valves  of  a  yielding  fulcrum  for  the  valve  lever, 
and  a  stud  or  stop  to  receive  and  support  the  valve-lever  as 
soon  as  the  fulcrum  commences  to  yield. 


STEAM  ENGINE. 


117 


Peefs  Tnventio7i. — The  accompanying  illustration  represents 
a  valve  patented  by  Mr  S.  J.  Peet,  of  New  York,  vv^hich  is  well 
spoken  of  on  account  of  the  simplicity  of  its  construction  and 
the  ease  with  which  it  may  be  repaired. 

From  the  engraving  representing  the  valve  in  section,  it  will 
be  seen  that  the  two  discs  serving  to  close  the  valve  are  raised 
or  depressed  by  means  of  the  hand-wheel  and  upright  stem  B. 
These  discs  are  suspended  on  the  stem  by  its  collar  engaging 
with  the  semicircular  recesses  on  their  inner  faces,  and  pre- 
vented from  separat- 
ing from  the  stem 
by  the  walls  of  the 
passage  in  which 
they  move.  The 
lower  face  of  the  col- 
lar, B,  and  the  lower 
portion  of  the  reces- 
ses in  the  discs  are 
made  slightly  coni- 
cal, so  that,  after  the 
discs  have  reached 
the  bottom,  any 
further  pressure  on 
them  by  the  screw 
of  the  stem  forces 
them  apart  and  firmly 
against  the  walls  of 
the  valve,  thoroughly 
closing  the  apertures 
of  the  pipe.  The 
conical  collar,  there- 
fore, acts  as  a  wedge  aided  by  the  pressure  of  the  screw, 
will  be  seen  that  both  sides  of  the  pipe  are  closed  by  this  means, 
making  this  a  back-pressure  valve  as  well  as  a  direct  acting 
gate.  When  the  discs  are  raised,  a  free  passage,  without 
change  of  direction,  is  made  through  the  valve  for  the  steam, 
water,  or  gas,  of  the  full  size  of  the  pipe.  The  stem  is  packed 
in  the  usual  manner  by  the  screw  gland  D. 


It 


Safety- Valve  Balance. — This  is  the  safety-valve  and  balance 
used  on  the  principal  railways.     The  lever  D,  fig.  i,  is  affixed 


ii8 


STEAM  ENGINE. 


to  a  spring  balance  A,  graduated  to  the  pressures  per  square 
inch  due  to  the  spring.  By  turning  a  nut  B  on  the  stem  of  the 
spring-balance,  any  required  pressure  can  be  thrown  upon  the 
valve,  which  is  kept  down  by  the  spring  acting  on  its  lever. 
Should  the  pressure  within  the  boiler  exceed  that  to  which  the 
balance  is  adjusted,  the  valve  is  opened,  and  a  portion  of  the 
steam  escapes.     The  lock-up  safety-valve,  fig.  2,  consists. of  a 

valve  pressed  down 
C.I  gt,     by  a  set  of  strong 

springs  C,the  whole 
enclosed  within  a 
box  under  lock 
and  key.  While 
the  engine  -  driver 
has  command  over 
the  spring-balance 
valve,  so  as  to  in- 
crease or  diminish 
the  load  at  plea- 
sure, the  lock-up 
valve  is  inacces- 
sible to  him,  and 
opens  whenever  he  has  loaded  the  open  valve  beyond  the 
pressure  to  which  the  lock-up  valve  has  been  adjusted ;  thus 
serving  as  a  check  upon  him  in  case  of  his  working  at  a  dan- 
gerous pressure. 


Safety- Valve  and  Superheater. — The  following  is  the 
arrangement  of  the  safety-valve  in  general  use  in  marine 
engines  : — A  is  a  handle  with  socket  attached,  the  outside  of 
which  socket  fits  into  the  top  of  dome  or  upper  part  of  valve- 
chest  B,  and  internally  fitting  the  valve-spindle  E.  D,  D,  &c,, 
are  the  lead  weights  entirely  enclosed  in^the  valve-chest  B,  C, 
which  is  generally  cut  in  two  for  the  purpose  of  removing  the 
weights  on  examining  the  valve  and  seat  F,  G.  Now  for  its 
action  through  the  sockets  of  A  and  the  upper  end  of  spindle  E,  a 
cotter  is  fitted  loosely  and  bored  in  the  point  to  receive  a  pad- 
lock, the  key  of  which  is  given  in  charge  to  the  captain  of  the 
vessel.  It  will  be  seen  that  the  cotter  hole  in  spindle  is  much 
longer  than  that  of  the  socket  A,  which  allows  the  valve  and 
weights  when  counterbalanced  by  the  pressure  in  the  boiler  to 


STEAM  ENGINE. 


19 


rise  sufficient  to  allow 
being  eased  by  hand 
in  the  engine  -  room, 
which  can  be  effected 
as  shown  by  the  dotted 
lines.  As  the  cotter 
rests  on  the  top  of 
the  projection  of  B,  it 
allows  the  valve  to  be 
moved  freely  on  its 
seat  at  any  time,  and 
at  the  same  time  pre- 
venting any  weight 
that  may  be  placed  on 
A  from  taking  effect 
on  the  valve.  The 
superheater  is  used  for 
the  purpose  of  drying 
the  steam  immediately 
after  its  generation  in 
the  boiler,  and  to  pre- 
vent as  much  as  pos- 
sible the  condensation 
of  the  same  while  on 
its  passage  from  the 
boiler  to  the  cylinder. 


a  free  escape  of  steam,  independent  of 


i.\j] L 


New  Slide- Valve. — This  equilibrium  sHde-valve  is  intended 


to  prevent  the  waste  of  steam  in  the  ports  of  cylinders.      C  is 


STEAM  ENGINE. 


->^- 


the  face  on  the  back  of  valve  BB,  the  movable  face  and  ex- 
haust-pipe E    is  the  set   screw    to    screw  down  'the    packing 


gland  with  crossbar  A.     Another  modification  of  the  valve  is 
shown  at  No.  2  ;  the  ports  in  this  valve  are  placed  to  one  side 
of  the  valve  face,  and  the  exhaust-pipe 
SECTION  BB   is  cast  to  the  back  of  the  valve, 

which  oscillates  on  the  centre  stud  D 
and  exhaust-pipe  BB,  covering  alter- 
nately the  top  and  bottom  ports. 


Safety- Valve. — This  safety-valve  is 
designed  for  a  small  cylindrical  (model) 
boiler,  12  in.  in  diameter  by  24  in.  in 
length. 

The  valve,  with  its  seat  and  dome, 
are  of  brass.  The  ball'  may  either 
be  solid  or  hollow.  Being  a  true 
sphere,  it  is  perfectly  free  to  move  in 
its  seat,  without  the  possibility  of  stick- 
ing, whenever  the  pressure  of  steam  in 
the  boiler  is  beyond  that  for  which  the 
lever  is  weighted.  The  dome  serves  to 
protect  and  guide  it  in  its  seat. 

A  serious  objection  to  many  of  the 
valves  now  in  use,  particularly  those  of 
the  "  mushroom ""  form  with  stem  and 
guide,  is  their  liability  to  stick,  and 
disastrous  results  have  often  happened 
Perfect  freedom  of  action  and  non-liability 


from  this  defect. 


STEAM  ENGINE. 


[21 


to  Stick,  are  therefore  important  features  in  the  construction  of 
a  safety-valve.     The  principle  of  the  ball  valve  is  not  new. 


A  New  Safety- Valve. — The  following  is  a  design  for  a 
safety-valve  which  will  register  the  pressure  of  steam  as  well  as 


allow  it  to  escape  : — The  valve,  it  will  be  perceived,  ascends  as 
the  pressure  increases,  and  descends  as  the  pressure  decreases. 


122 


STEAM  ENGINE. 


BB  are  two  bars  fixed  for  the  valve-rod  to  slide  through  to 
guide.  At  the  top  of  the  valve-rod  R,  there  will  be  perceived 
a  small  roller  to  make  it  run  free  under  the  lever  L. 

Slide- Valve  Motion. — Many  possessors  of  small  cylinders 
— say  I  J-in.  bore  and  3 -in.  stroke,  with  steam  chest  on  top — 
are  puzzled  to  know  how  to  communicate  motion  to  the  slide- 


valve,  so  as  to  be  out  of  the  way  of  the  crank  and  the  connect- 
ing-rod. The  following  plans  will  suffice  : — ^,  the  cylinder,  b, 
brackets  screwed  on  back  of  cylinder  flange  carrying  shaft  c, 
on  which  is  fixed  two  arms  d^  d^  one  connected  with  the  eccen- 
tric and  the  other  to  give  motion  to  the  valve.  The  arm  d' 
has  a  slot  for  changing  the  length  of  stroke  :   the  connecting-rod 


STEAM  ENGINE. 


23 


is  screwed  into  the  eccentric  strap  for  setting  valve  with  the  nut 
e  for  tightening  when  set, /is  the  support  for  valve-rod. 


Another  method  is  shown  in  this  diagram,  which  sufficient!} 
explains  itself. 


[24 


STEAM  ENGINE. 


Another  plan:  A,  Crankshaft;  B,  fly;  C,  eccentric;  D,  horizon- 
tal lever  with  eccentric-rod  on  one  end,  valve-rod  on  the  other. 


The  following  plan  is  generally  adapted  to  cylinders  with 
valve  on  top  : — It  is  a  spindle  on  brackets,  with  lever  near  the 


middle,  connected  with  the  valve-spindle  by  two  links.     A  nut, 


•  STEAM  ENGINE. 


125 


with  a  pin  formed  on  each  side,  is  taped  and  screwed  on  the 
valve-spindle,  in  order  that  the  valve  may  be  set  to  a  nicety  to 
the  end  of  the  spindle,  fig.  3.  Another  lever  is  fixed,  with  a 
long  hole  at  the  end,  and  a  pin  is  inserted  on  which  hangs  the 


eccentric-rod.  By  having  a  long  hole  and  movable  pin,  the 
stroke  of  the  valve  may  be  set  to  the  desired  length.  Fig.  i  is  a 
plan;  fig.  2,  elevation;  fig.  3  shows  the  rocking-shaft  or  spindle 
laid  with  the  levers  and  links  attached  to  the  valve  spindle. 

Another  method  is  shown  in  next  diagram  :  — A  is  sole  plate, 
B  cylinder,  C  connecting-rod,  D   rocking-shaft,    E    levers  on 


1       \ 

IB    ^     ^1" 

t  ^ 

^2^=^= 

A 

"^ 

rocking-shaft,  F  pedestals  to  carry  rocking-shaft,  G  eccentric- 
rod,  H  connecting-rod  for  slide-valve. 

Reversing  Motion  in  Engines. — The  following  is  a  simple 
arrangement  for  altering  an  engine,  so  that  you  may  reverse  it 
at  will,  which  can  be  done  according  to  this  plan  with  one 


126 


STEAM  ENGINE. 


eccentric,  and  doing  away  with  eccentric-rod,  and  using  a  longer 
valve-rod  and  a  link  : — Fix  a  plate  to  the  eccentric-strap,  and 
also  a  link  (as  will  be  seen  in  sketch)  extending  from  D  to  D'. 


B  is  a  rock-shaft  working  on  a  pin  fixed  to  centre  of  plate,  it 
and  another  pin  fixed  at  F  on  a  plate  bolted  to  engine-stand. 
When  the  engine  is  at  work  the  rock-shaft  will  give  motion  to 
link  as  if  using  two  eccentrics  ;  and  by  moving  the  lever  G  to 
the  dotted  lines  G^,  the  sliding-block  will  be  moved  from  its 
position  at  top  of  link  (as  seen  in  sketch)  to  the  bottom  of  link, 
and  so  alter  position  of  slide-valve  and  reverse  the  engine  ;  and 
by  moving  the  lever  G  into  some  of  the  notches  marked  at  H, 
the  travel  of  valve  will  be  short,  and  so  allow  the  steam  in 
cylinder  to  expand  by  closing  the  ports  sooner,  and  allowing 
less  steam  to  enter  the  cylinder.  The  parts  G,  H,  J,  K,  and  L 
can  be  fixed  to  engine-frame  or  stand  in  any  position  best 
suited  to  the  plan  of  engine. 

Setting  the  Slide- Valve. — First,  the  steam  is  to  be  shut 


STEAM  ENGINE. 


[27 


off  a  little  before  the  end  of  the  stroke  by  closing  the  aperture 
of  the  steam-port  which  causes  the  piston  to  be  brought  gradu- 
ally to  rest  without  jarring  the  engine.  Secondly,  the  eduction- 
port  or  passage  to  condenser  should  be  closed  before  the  end 
of  stroke,  which  is  called  "  cushioning  "  the  piston,  because  it 
then  completes  the  stroke  against  an  elastic  air-cushion  in  con- 
sequence of  a  portion  of  uncondensed  vapour  being  shut  up 
between  the  piston  and  the  top  or  bottom  of  cylinder.  Thirdly, 
the  steam-port  on  the  same  side  of  the  piston  should  be  opened 
a  very  little  before  the  end  of  the  stroke,  so  that  the  steam  may 
have  acquired  its  full  pressure  as  soon  as  the  crank  shall  have 
turned  the  centre ;  and  lastly,  the  communication  with  con- 
denser should  also  be  opened  on  the  opposite  side  of  the  piston 
a  little  before  the  end  of  stroke,  so  as  to  have  a  vacuum  ready 
made  in  the  cylinder  before  the  return  stroke  begins. 


Boiler  Feeding. — Several  modes  of  feeding  a  boiler  without 
a  pump  have  been  suggested  from  time  to  time,  but  the  follow- 
ing will  be  found 
practicable  :  —  A 
is  the  steam-boil- 
er, and  B  a  tank 
some  distance 
above ;  is  fed  by 
a  pipe  F,  with  a 
fiap-valve  opening 
into  the  tank  as 
shown.  This  tank 
is  also  connected 
with  the  boiler  by 
two  pipes  C  D,  in 

each  of  which  is  a  cock  C  D'  connected  by  levers  with  slotted 
eyes  to  a  pin,  on  the  end  of  a  rod  of  iron  H  ;  the  other  end  of 
the  rod  is  coupled  to  the  float  E  inside  the  boiler. 

The  action  is  as  follows  : — Suppose  the  water  in  the  boiler 
was  to  get  low,  then  the  float  E  would  go  down  with  it,  bring 
down  the  slotted  levers  and  open  the  cocks  O  D'  in  the  pipes 
C  D,  which  would  open  two  communications  between  the  boiler 
A  and  the  tank  B  ;  the  pipe  C  letting  steam  into  the  tank  and 
forcing  the  water  down  the  pipe  D  till  the  water  in  the  boiler 
regains  its  level  when  the  float  rises,  shuts  the  two  cocks,  and 


128 


STEAM  ENGINE. 


cuts  off  the  communication  with  the  tank,  which  then  fills  again 
through  the  pipe  F.  The  flap-valve  is  to  prevent  the  water 
returning  down  the  pipe  F. 

Boiler  Construction. — The  fire  tubes  passing  through  the 
steam  space  of  boiler  would  not  heat  the  steam,  but  would  con- 
dense it,  in  proof  of  which 
an  egg-shaped  boiler  in 
work  had  the  flues  built 
2  inches  higher  than  the 
water-line,  and  was  in 
consequence  unable  to 
keep  up  a  constant  sup- 
ply of  steam.  But  when 
the  flues  were  lowered 
2  inches  below  the  water- 
line,  a  sufficient  supply 
was  kept  up.  The  up- 
per tube  plate,  though 
placed  in  a  horizontal  position,  would  not  impede  the  rising  of 
the  steam.  The  dotted  line  in  sketch  shows  where  the  flues 
were  lowered  to. 

Boiler  Working. — An  old  rule  for   Cornish,  and   2-flued 

boilers,  is  to  allow  5 
square  feet  of  water 
surface  per  horse- 
power of  boiler;  there- 
fore we  make  the  total 
boiler  horse-power 
from  I J  times  to  2 
times  the  nominal 
horse-power  of  engine 


E^ 


Kemp 


Steam -Propeller 
for  Model  Boats. — 

Various  contrivances 
have  been  adopted 
from  time  to  time 
for  propelling  small 
boats.  Mr  W.  G. 
boiler  ;   B,  furnace  ;   C, 


STEAM  ENGINE. 


129 


steam-pipes  ;   D,  safety-valve  ;  E,  guage  tap.     The  steam-pipes 
should  be  made  of  indiarubber. 

This,  on  examination  and  trial,  proved  to  be  a  failure,  as  the 
steam  condensed  with  propelling  the  boat ;  but  it  was  found 
that,  if  the  end  of  the  steam-pipe  were  brought  to  a  point  with 
a  very  small  hole  in  it,  and  inserted  into  another  pipe,  so 
shaped  as  to  leave  a  space  all  round  the  entrance  of  the  point  of 
the  steam-pipe,  the  rush  of  the  steam  drew  in  with  it  a  quantity 
of  air,  which  it  forced  out  of  the  stern  of  the  boat,  and  conse- 
quently forced  it  through  the  water  at  a  very  fair  speed.  It 
answered  better  when  the  keel  of  the  boat  was  made  wide  at 
the  stern,  and  two  thin  pieces  of  metal  were  fastened  on  the 
side,  so  as  to  force  ^.^^ 

the  air  direct  astern,  ^^^5 

than  when  the  pipe 
alone  was  brought 
through. 

A,  pieces  of  thin 
metal  fastened  each 
side  of  keel ;  B, 
point  of  steam-pipe 
entered  into  the  air-pipe;  C,  steam  tap  ;  D,  D,  water-level  taps  ; 
E,  spring  safety-valve ;  G,  pipe  attached  to  valve  to  carry  off 
waste  steam  ;   F,  water  level ;   H,  spirit  lamp. 

Another  7nethod  is  described  in  the  following  diagram  : — A, 
a  hollow  ball ;  B, 
steam  -  pipe  from 
boiler  to  ball ;  C, 
pipe  from  ball 
through  bottom  of 
boat ;  and  D,  pipe 
from  ball  through 
stern  of  boat.  To 
the  end  of  steam- 
pipe  B  is  attached 
a  nozzle,  which  pro- 
jects within  the  ball 
fullypast  its  centre, 
about  in  a  hne  with 
the  far  side  of  pipe  C,  as  shown  by  dotted  Hues  at  E.  The 
force  of  the  steam  in  rushing  through  the  nozzle  tends  to  form 

I 


I30  RAILWAYS  AND  LOCOMOTIVES. 

a  vacuum  within  the  ball ;  immediately  the  water  rushes  up  the 
pipe  C,  and,  being  caught  by  the  steam,  is  forced  through  the 
pipe,  and  so  keeps  up  a  continuous  stream. 

The  general  principle  of  the  screw-propeller  may  be  thus 
described  : — If  a  thread  be  wound  upon  a  cylinder  equal  dis- 
tances apart,  it  will  trace  a  single-threaded  screw  ;  if  another 
thread  be  wound  on  the  same  cylinder  between  the  first  thread, 
they  will  trace  a  double-threaded  screw.  Now,  if  the  threads 
be  supposed  to  be  raised  into  a  very  deep  and  thin  spiral 
feather,  and  the  cylinder  be  supposed  to  become  very  small, 
then  a  screw  of  the  proper  kind  will  be  obtained  for  propelling 
vessels,  except  that  only  a  small  piece  of  such  screw  must  be 
employed.  A  two-bladed  propeller  is  a  short  piece  of  a  double- 
threaded  screw,  a  three-bladed  propeller  is  a  short  piece  of  a 
triple-threaded  screw.  The  diameter  of  the  screw  is  the  circle 
described  by  the  extremities  of  the  arms,  the  pitch  is  the  dis- 
tance in  the  line  of  the  shaft  from  one  convolution  to  the  next. 
Sometimes  screws  are  made  with  an  increasing  pitch  in  the 
direction  of  their  length,  also  from  centre  to  circumference. 
The  original  screw  propellers  were  made  with  several  convolu- 
tions, but  are  now  reduced  to  about  i-6th  of  a  convolution. 
The  term  length  indicates  what  portion  of  a  convolution  is 
employed.  If  a  screw  of  9  ft.  pitch  has  i-6th  of  a  convolution, 
the  length  will  be  i  ft.  6  in.  The  slip  of  the  screw  is  the  differ- 
ence between  the  actual  speed  of  the  vessel  and  the  speed  it 
should  attain  if  the  screw  worked  in  a  solid  nut ;  this  is  called 
the  positive  slip.  There  is  also  the  negative  slip,  where  the 
velocity  of  the  vessel  is  actually  greater  than  if  the  screw 
worked  in  a  solid  nut,  though  the  latter  is  not  of  very  frequent 
occurrence. 

Railway  Signals. —  All  travellers  by  railway  are  familiar 
with  the  ordinary  mode  of  signalling  by  means  of  movable 
arms  or  semaphores  and  lights,  and  probably  not  a  few  of  them 
are  acquainted  with  the  signalman's  jingle — 


"  White  for  right,  red  for  wrong, 
And  green  for  gently  go  along  ! 


But  the  best  system  is  that  now  adopted,  first,  we  believe,  on  the 
South-Western  system. 

After  the  introduction  of  Mr  Preece's  plan  of  Block  Signalling 
on  the  South-Western,  these  repeaters,  which  are  similar  in 


RAILWAYS  AND  LOCOMOTIVES. 


FIG.  I. 


FHONT 


VIEW, 


construction  to  the  block  instruments,  were  fixed  in  one  or  two 
places  for  experiment,  and  the  experiment  was  so  successful,  and 
their  use  so  valuable,  that  they  were  gradually  extended. 

The  great  merit  in  these 
signal  instruments  is  the  assi- 
milation of  the  indoor  or  block- 
signal  to  the  outdoor,  so  that 
if  a  semaphore,  disc,  or  other 
signal  be  used  on  the  line  to 
warn  the  engine-driver,  the 
man  who  has  that  signal  under 
his  control  is  himself  in  the 
first  place  warned  by  a  similar, 
but  miniature,  semaphore  or 
disc  inside  his  box,  so  that 
where  it  is  necessary  that  a 
signal  should  be  repeated  and 
made  visible  to  the  signalman, 
the  signal  in  his  box  is  made 
similar  in  form,  but  in  minia- 
ture, to  the  outdoor  signal 
itself.  Every  motion,  there- 
fore, of  the  signal- lever  would 
produce  a  corresponding  result 
upon  the  small  signal,  enabling 
the  signalman  to  see  instantly 
whether  all  was  right. 

In  fig.  I  will  be  seen  a  front 
view  of  a  small  semaphore  ; 
fig.  2  shows  an  elevation  of 
the  interior  arrangements,  both 
of  them  showing  the  sema- 
phore arm  down,  giving  the 
"  All  clear "  signal.  A  is  a 
strong  horse-shoe  electro-mag- 
net fixed  at  the  bottom  of  the 
box.  B  is  the  armature  pivot- 
ed at  G,  and  weighted  at  W 
by  a  small  weight,  which  is  made  to  sHde  up  or  down  the 
armature  lever  between  G  and  C.  At  the  end  of  this  lever,  at 
C,  is  attached  a  long  lever  to  the  head  of  the  semaphore  arm. 


[32 


/RAILWAYS  AND  LOCOMOTIVES. 


The  armature  has  a  Hmit  to  its  movements  by  the  stops  at  F 
and  E. 

It  will  be  seen  that  any  motion  up  or  down  of  the  armature 
must  exercise  an  opposite  motion  of  the  long  lever  CD,  and 
exercise  an  influence  upon  the  arm  to  raise  or  depress  it.  A 
current  of  electricity  passing  through  the  electro -magnet  would 

at  once  exercise  mag- 
netic effect,  and  cause 
the  armature  to  be 
attracted ;  this  would 
have  for  effect  the 
immediate  raising  of 
the  semaphore  arm, 
which  would  remain 
in  that  position  so 
long  as  a  current 
flowed  round  the 
magnet;  immediately 
on  the  cessation  of 
the  current,  the  elec- 
tro -  magnet  would 
cease  its  action,  the 
armature  would,  by 
reason  of  the  weight 
W,  be  restored  to  its 
original  position,  and 
the  arm  would  fall 
and  give  the  "  All 
clear"  signal,  as  in 
the  diagram.  It  will 
be  seen,  therefore, 
that  by  the  action 
and  cessation  of  a 
current  we  can  raise 
or  depress  a  sema- 
phore arm ;  and  that 
if  there  be  contrived 
some  automatic  arrangement  in  connection  with  the  outdoor 
signal  to  effect  this  object,  we  have  at  once  a  faithful  repeater 
in  the  signalman's  box  of  the  outdoor  signal,  however  distant  it 
may  be. 


RAILWAYS  AND  LOCOMOTIVES.  133 

Such  an  arrangement  as  the  following  has  been  adopted.  At 
the  head  of  the  semaphore,  close  to  where  the  arm  is  pivoted, 
are  fixed,  one  on  each  side,  and  insulated  from  each  other,  two 
springs,  the  one  in  connection  with  a  live  wire  to  the  signal- 
man's box,  where  it  is  attached  to  one  end  of  the  electro- 
magnet, the  other  spring  is  in  direct  communication  with  the 
earth.  Upon  the  arm  itself  is  fixed  a  piece  of  brass,  so  that 
when  the  arm  is  raised  it  presses  up  between  the  two  springs 
and  completes  the  circuit,  but  only  when  the  arm  is  almost 
fully  raised.  In  the  signalman's  hut  is  placed  a  battery,  one 
pole  of  which  is  to  earth,  the  other  to  the  electro-magnet.  The 
battery  circuit  is,  therefore,  through  the  electro-magnet,  insula- 
tion taking  place  at  the  spring  of  the  semaphore.  In  this 
position,  therefore,  the  miniature  semaphore  is  at  "  All  clear  " 
the  same  as  the  distant  signal  itself.  Immediately  the  signal- 
man moves  his  lever  to  alter  the  signal,  the  arm  is  raised,  the 
brass  piece  on  the  arm  completes  the  electric  connection 
between  the  insulated  spring  and  the  earth  spring,  the  battery 
is  at  once  brought  into  play,  the  magnet  acts,  the  armature  is 
attracted,  and  the  small  semaphore  arm  is  raised  to  "  Danger," 
corresponding  with  the  outdoor  signal.  The  whole  of  this 
takes  place  in  a  far  shorter  time  than  it  has  taken  us  to 
describe.  The  action  is  almost  immediate ;  so  long,  therefore, 
as  the  arm  is  raised  to  the  position  of  "  Danger,"  the  miniature 
arm  faithfully  reflects  that  position  ;  but  as  soon  as  the  lever 
is  restored  to  its  original  position,  the  distant  signal  is  lowered, 
the  circuit  is  broken,  and  the  armature  is  at  once  released,  the 
small  arm  therefore  falls,  and  shows  the  state  of  the  distant 
signal.  Should  the  miniature  arm  remain  down  when  the 
signalman  puts  his  lever  over,  he  is  at  once  aware  that  his  wire 
or  part  of  the  signal  apparatus  is  out  of  order,  and  would  con- 
sequently take  immediate  steps  to  put  it  right. 

In  order  that  the  battery  may  not  be  wasted,  it  is  arranged 
that  the  signal  which  is  used  less  than  the  other  should  attract 
the  armature  :  thus  at  a  junction  the  "  Danger  "  signal  is  con- 
stantly in  use,  the  "  All  clear  "  only  to  admit  a  train.  At  a 
station  the  distant  signal  is  generally  at  "  All  clear."  So  in 
the  one  case  we  want  the  armature  when  attracted  to  lower  the 
arm,  and  in  the  other  to  raise  it.  By  referring  to  the  sketch, 
the  attraction  of  the  armature  will  in  this  case  raise  the  arm  ; 
but  if  the  lever  on  the  arm  be  fixed  in  front  instead  of  behind 


134 


RAILWAYS  AND  LOCOMOTIVES. 


the  pivot  D,  the  attraction  will  raise  it,  and  vice  versd.  When 
it  is  necessary  that  the  "  All  clear ''  signal  or  the  lowering  of 
the  arm  should  bring  the  battery  into  play,  then  the  insulated 
springs  must  be  placed  at  the  back  of  the  semaphore,  and  the 
brass  connecting-piece  at  the  back  of  the  arm.  When  so 
placed,  no  current  is  passing  when  the  arm  is  raised  ;  the  re- 
peater, by  gravity,  has  its  arm  up  ;  but  when  the  signal-arm  is 
lowered,  it  makes  connection,  the  electro-magnet  is  brought  into 
play,  and  the  small  arm  is  lowered. 

As  semaphores  are  now  being  generally  adopted  everywhere, 
we  have  described  the  arrangement  adopted,  but  on  various 

lines  there  are  differ- 
ent signals  in  action 
to  which  these  re- 
peaters are  equally 
applicable.  On  the 
South  -  Western  the 
disc,  on  the  Great 
Western  and  North- 
western the  disc  and 
bar,  as  the  following 
sketches,  3  and  4, 
show.  Instead  of  an 
up-and-down  motion, 
these  signals  are  al- 
tered by  a  circular 
movement.  In  fig. 
4  is  a  miniature 
"  disc,"  the  interior 
arrangement  of  the 
electro  -  magnet  is 
similar,  but  at  the  end  of  the  armature  is  placed  a  rack  which 
works  into  a  pinion  fixed  on  the  rod  that  carries  the  disc.  The 
attraction  and  release  of  the  armature  conveys  a  circular  motion 
to  the  rod  ;  the  disc  is  consequently  moved  from  the  one  posi- 
tion denoting  "  Danger "  to  the  other  denoting  "  All  clear." 
As  the  motion  of  the  disc  outdoor  is  different  to  that  of  the 
semaphore,  the  connection  necessary  to  put  the  live  wire  to 
earth  is  consequently  different. 

Upon  the  wooden  upright  that  carries  the  disc-rod  is  placed 
a  piece  of  brass,  fitted  with  a  spring  to  ensure  contact ;  this  is 


RAILWAYS  AND  LOCOMOTIVES. 


^35 


properly  connected,  and  is  protected  from  wet  by  an  iron  roof. 
Upon  the  rod  which  is  in  connection  with  the  earth  is  fixed  a 
second  piece  of  brass  with  a  spring ;  this  is  fixed  at  the  same 
height,  and  is  so  connected  that  when  the  disc  is  turned  these 
springs  make  a  good  rubbing  contact. 

The  action  is  of  course  similar  to  that  of  the  semaphore  : 
immediately  the  lever  is  pulled,  the  disc  turns  round  and  the 
springs  make  connection,  the  armature  of  the  miniature  disc  is 
attracted,  and  by  the  rack-and- 
pinion  movement  the  disc  is 
turned  into  a  position  corres- 
ponding with  the  outdoor  signal. 
When  the  disc  is  turned  the 
opposite  way,  or  to  "  All  clear," 
contact  is  broken,  the  weighted 
armature  falls  back,  and  "  All 
clear"  is  shown  in  the  signal- 
man's hut.  The  contact  arrange- 
ment on  the  outdoor  signal  is 
similar  to  what  would  be  applied 
to  signals  such  as  are  used  on 
the  Great  Western.  To  make 
the  miniature  signal  agree,  it  is 
only  necessary  to  fix,  instead  of 
the  disc,  a  disc  and  bar,  as  in 

fig.  3. 

Many  of  the  discs  and  sema- 
phore repeaters  have  been  fixed 
on  the  South- Western  and  other 
lines  for  some  years  ;  they  give 
great  satisfaction,  and  continue 
to  work  well.  In  places  where, 
during  fine  weather,  the  signal  is 

visible,  yet  in  consequence  of  the  place  being  situated  low,  and 
being  liable  to  fog,  there  are  very  many  days  in  the  year  when 
the  signal  is  invisible.  In  such  places  some  extra  precaution 
of  this  nature  should  be  taken. 


Electric  Railway  Signal. — The  object  of  this  new  appa- 
ratus  is  to  prevent  the  possibiUty  of  a  signalman  signaUing  that 
the  line  is  clear  until  the  train  which  should  control  his  move- 


136 


RAILWAYS  AND  LOCOMOTIVES. 


merits  has  actually  passed  his  box.  There  is  applied  to  the 
switch  or  lever  of  the  railway- signal  telegraph  apparatus  a  means 
of  locking  the  handle  or  lever  after  it  has  been  used  to  adjust 
a  signal,  and  of  retaining  it  in  a  fixed  position  until  released  by 
the  action  of  a  passing  train,  which  will  remove  the  cause  for 
retaining,  say,  the  danger-signal  in  a  fixed  position. 

Fig.  I  is  a  back  view  of  the  apparatus,  fig.   2  an  inverted 
plan  view,  and  fig.  3  a  vertical  section  taken  in  the  line  1,2, 


I 

oi  fig.  2.  The  switch- lever  apparatus  is  connected  (as  shown 
at  A,  fig.  4)  with  the  railway  by  an  arrangement  of  levers  and 
rods,  which  are  set  in  action  by  the  passing  train  for  the  pur- 
pose of  withdrawing  a  restraining  bolt  applied  to  the  handle  or 
lever  of  the  switch  apparatus,  and  thereby  leaving  it  free  to  be 
set  in  action  by  the  signalman. 


RAIL  WA  YS  AND  LOCOMO  TIVES.  137 

a  is  the  handle  or  lever  of  the  switch  apparatus  mounted  on 
a  centre  at  b,  the  bearing  for  which  is  insulated  by  being  let 
into  a  table  of  wood  c.  Fitted  to  opposite  sides  of  the  switch 
handle  are  the  spring-clips  a"  a",  which  are  inten4|^^/ 
the  divided  bridge  or  insulated  segment-plates  d  ^,  "goDfi-ec! 
by  clamping  nuts  e  e^,  to  electric  wires  leading  to  vthe  terminus- .-. 
e^  e^.  The  switch-lever  is  also  in  metallic  coijftact  with  a  wire 
leading  to  the  terminal  e^.  A  pin  a^  at  the  Idwer  end  of  the 
switch-lever  a  projects  into  the  forked  end  />f  a  beU-crank 
lever  /,  mounted  on  the  under  side  of  the  table^  and  fitted  at 
its  opposite  end  with  a  spring  catch  or  tumberC/^,  As  this 
switch-lever  a  is  moved  it  will  give  a  rocking'  motion  to  the 
bell-crank  lever,  for  the  purpose  to  be  presently  emlained.  The " 
lower  part  of  the  switch-lever  has  a  notch  cut  %iyt^  $dge',iD '"" 
receive  a  sliding  bolt  g,  by  which  it  is  locked  in  its^Tlmmal 
position.  This  bolt  is  carried  by  a  slotted  guide-bar  g"-  through 
the  slots  of  which  screws  are  passed  for  securing  it  to  brackets 
attached  to  the  under  side  of  the  table.  This  guide-bar  is  pro- 
vided on  its  face  with  a  pin  g^,  against  which  the  spring-catch 
f^  is  intended  to  strike  in  one  direction  of  its  motion,  for  the 
purpose  of  driving  that  bar  forward,  but  on  its  return  motion 
the  spring-catch  slides  over  the  pin.  Upon  the  edge  of  the 
guide-bar  is  a  second  pin  or  projection  g^,  through  which  the 
bar  receives  an  endway  motion  in  the  opposite  direction  to  that 
imparted  by  the  bell- crank.  This  pin  g^  is  acted  upon  by  a 
pendant-lever  h,  which  is  itself  acted  upon  by  a  vertical  rock- 
lever  i,  fig.  4,  connected  at  its  lower  end  to  a  sliding-rod  h  ; 
this  rod  k  is  caused  to  bear  against  a  horizontal-lever  or  switch 
/,  applied  to  the  railway  track,  as  shown  at  fig.  4 ;  and  in  plan 
view  at  fig.  5,  a  spring  w,  or  a  weight,  being  used  to  keep  the 
rod  up  to  its  bearing.  Supposing  now  a  train  to  be  passing 
along  a  line  fitted  with  the  locking  apparatus  above  described 
in  the  direction  of  the  arrow,  fig.  5,  the  switch  or  lever  /will, 
by  the  lateral  pressure  it  will  receive  from  the  flange-wheels 
passing  between  it  and  the  fixed  rail,  be  rocked,  and  it  will  thus 
give  an  endway  motion  to  the  rod  or  tracker  k,  which  will  in 
its  turn  rock  the  levers  z  and  h,  and  the  latter,  striking  against 
the  pin  on  the  bar  g'',  will  drive  it  and  the  bolt  which  it  carries 
into  the  dotted  position  of  fig.  2.  The  switch-lever  will,  there- 
fore, be  free  to  be  moved  from  the  drawn  to  the  dotted  position 
of  fig.  3,  for  the  purpose  of  operating  a  distant  signal. 


138  RAILWA  YS  AND  LOCOMOTIVES. 

As  this  apparatus  is  specially  adapted  for  use  with  Mr 
Preece's  block-signal  telegraph  apparatus,  in  which  the  sema- 
phore arm  is  maintained  by  a  weight  and  depressed  by  the 
action  of  the  electric  current,  it  is  used  in  the  following  manner, 
viz.  : — The  terminal  e^  is  connected  with  the  earth,  the  terminal 
e^  with  the  battery,  and  the  terminal  e^  with  the  line  wire. 
When,  therefore,  the  hand-lever  is  in  the  drawn  position  of  fig. 
3,  which  is  its  normal  position,  there  is  no  current  passing 
through  the  distant  signal  apparatus  which  the  switch  apparatus 
is  intended  to  control,  and  the  block-signal  is  consequently  up; 
on  the  other  hand,  when  the  hand-lever  is  in  the  dotted  posi- 
tion, the  current  will  pass  through  the  distant  signal  apparatus, 
and  retain  the  semaphore  arm  at  the  depressed  position,  thereby 
indicating  "  line  open."  If  now  the  signalman  at  the  distant 
station  A  signals  to  the  man  at  station  B,  that  a  train  has 
started  from  A  in  the  direction  of  station  B,  the  duty  of  the 
receiver  of  this  signal  will  be  immediately  to  raise  the  block- 
signal  at  station  A  ;  this  he  will  do  by  throwing  over  the 
switch-lever  B  into  the  drawn  position  ;  but  in  the  act  of  doing 
this  he  will  cause  the  bell-crank  lever  f  to  strike  the  pin  g^  on 
the  shding-bar  ^o-^,  and  throw  the  bolt  g  into  the  notch  of  the 
switch-lever ;  the  lever  will  therefore  remain  fixed,  and  be 
beyond  tlie  control  of  the  signalman  at  station  B.  As  soon, 
however,  as  the  advancing  train  passes  the  switch  or  lever  /, 
and  sets  the  rod  k  and  lever  /  h  in  motion,  as  above  explained, 
the  guide-bar  g^  and  bolt  g  will  be  returned  to  the  dotted  posi- 
tion of  fig.  2,  and  the  signalman  will  then  be  able  to  set  his 
switch  apparatus  in  action.  If,  however,  he  should  delay  in 
communicating  the  proper  signal  to  station  A  that  the  line  is 
open,  no  casualty  can  arise,  the  only  inconvenience  being  the 
undue  blocking  of  the  line. 

This  apparatus  is  in  practical  operation  on  the  London  and 
South- Western  Railway,  and  is  spoken  of  very  highly. 

Fog  Signals. — The  following  plan,  if  capable  of  being 
reduced  to  practice,  would  displace  the  explosive  fog  signals 
now  in  use.  It  also  acts  as  a  distant  signal.  The  original 
part  of  the  proposal  is  the  adaptation  of  the  bell-crank  lever  H, 
so  as  to  strike  a  bell  F  in  a  passing  train  by  means  of  a  lever 
G,  or  similar  contrivance  placed  outside  the  guard's  van  and 
engine.      It  will  be  seen  by  looking  at  the  dotted  lines  that 


/RAILWAYS  AND  LOCOMOTIVES. 


39 


when  the  semaphore  L  is  down,  the  lever  B  is  lowered,  and 

causes  H  to  fall  below  the  level  of  the  lever  G,  attached  to  the 

train.     Therefore,  only  when  the  semaphore  is  at  danger  is  the 

bell  struck  to  warn 

the      guard      and 

driver.     The  lever 

H    is    put    so    far 

down  the  line  as  to 

enable   the    driver 

to   stop   the    train 

on  arriving  at  the 

semaphore  post. 

A,  signal-post ; 
B,  lever,  with 
weight ;  C,  wheel 
at  the  signal-box  or 
station;  D,  railway 
line  ;  E,  hammer  ; 
F,  bell;  G,  lever, 
with  weight  ;  H, 
bell-crank  lever ;  I, 
chain  to  connect  H  with 
L,  semaphore. 


B  ;    K,   chain  to  connect  C  with  B  ; 


TTcTa       PLAN 


Self- Acting  Railway  Signals. — i.  Below  is  a  self-acting 
signal,  said  to  possess  advantages  over  previously-invented 
plans  of  self-acting 


signalling.  Fig.  i 
is  an  elevation ; 
fig.  2  a  plan.  The 
same  figures  refer 
to  both  drawings. 
On  the  train  pass- 
ing the  post,  A 
strikes  the  lever  B, 
and  causes  the  sig- 
nal C,  which  is 
provided  with  a 
lamp  for  night  sig- 
nals, to  turn  to  danger,  the  lever  B  on  being  struck  causes  the 
wire  or  rod  'D  to  move  in  a  forward  position,  so  that  when  the 


FJ  C.  I        EL  EVATI  0  N 


140 


RAILWAYS  AND  LOCOMOTIVES. 


train  reaches  the  lever  E  the  signal  is  put  to  "  All  right."     F 
are  the  rails. 

2.  The  next  self-acting  apparatus  we  shall  describe  is  in- 
tended to  be  fixed  on  the  side  of  the  permanent  way. 


Fig.  I  is  a  front  view,  showing  all  ready  for  the  first  wheel 
of  the  engine  or  carriage  to  press  it  down  on  the  lever  D.  Fig. 
2  is  an  end  view,  showing  other  working  parts  of  the  appa- 


JRAILWAYS  AND  LOCOMOTIVES.  141 

ratus,  with  the  signal,  fig.  4,  attached  to  the  lever  P.      Fig.  3 
is  a  top  view. 

Suppose  a  train  coming  up  to  where  a  signal  is  placed.  The 
wheel  L  in  fig.  i  comes  on  the  lever  D,  passing  down  which 
is  a  slide-bar,  having  a  square  or  round  hole  K  in  the  middle, 
a  little  lower  down  a  cross-pin  or  the  eye-lever,  and  at  the 
bottom  a  joint  for  lever  P.  At  S  is  a  powerful  spring  to  lift  up 
the  slide-bar  C.  When  C  is  brought  down,  peg  F  is  forced  by 
the  spring  G  under  the  hole  K,  and  working  the  lever  P  brings 
the  signal  up  for  the  next  train.  N  is  a  strong  elastic,  fitted  to 
take  the  sudden  jerk  which  the  engine  would  make.  H  is  the 
eye-bolt  for  the  peg  to  work  in,  I  is  to  fasten  wire,  and  J  to 
plug  or  peg  F.  Suppose  the  train  has  passed  over  the  lever  D, 
down  goes  the  bar  C,  in  goes  the  peg  F  to  the  hole  K,  which  is 
a  great  deal  larger.  The  first  signal  is  up,  and  now  we  come 
to  the  second,  just  similar  to  fig.  i  ;  the  wire  JJ  is  attached  to 
the  wire  J  in  the  first  one,  and  by  passing  over  the  second  one 
works  the  lever  M,  withdraws  plug  F,  and  by  the  action  of  the 
powerful  spring  at  the  bottom,  up  comes  the  bar  C  on  lever  D, 
and  down  goes  the  signals,  the  one  that  we  commenced  with 
reacting  for  the  next  train  to  come  to  the  second  signal ;  and 
the  signalman  can  tell  whether  the  first  train  has  passed  over 
the  third  apparatus  by  seeing  whether  the  signal  is  down  or  not. 
The  latter  train  cannot  run  into  the  other  unless  the  signals  are 
neglected.     [There  is  considerable  ingenuity  in  this  idea.] 

Railway  Brakes.- — The  following  is  perhaps  more  suited 
for  goods  than  for  passenger  trains.      It  should  be  fixed  on 
both  sides  of  every 
truck  of  the  train. 

a  is  the  cill  of 
the  truck,  bb  the 
irons  connected 
with  the  wheels,  c 
the  rail  to  tie  in 
-the  wheels,  ^  is  a 

stud  on  the  brake  of  which  ec  swings,  /  is  a  lever  in  the  centre 
of  the  truck,  ^  is  a  spring  to  keep  off  the  brake.  In  case  of 
danger,  the  driver  would  tighten  the  wire-rope  kh.  This  would 
raise  the  lever  /,  which  would  bring  the  ends  of  the  brakes  in 
contact  with  the  rim  of  the  wheels.     These  would  lav  hold  of 


I4'2 


RAILWAYS  AND  LOCOMOTIVES. 


the  brake,  and  force  it  on  so  tightly  that  the  wheels  must  skid. 
[This  idea  has  not,  we  believe,  been  investigated  with  any 
practical  result.] 

Communication  between  Passenger  and  Guard. — Among 
the  suggested  means  of  arresting  the  attention  of  railway  guards 
by  passengers  in  the  carriages,  the  following  crude  ideas  have 
some  claim  to  attention  : — 

I.  This  consists  of  a  circular  tube,  which  is  fastened  in  the 
interior  of  the  panel  which  divides  the  compartments  to  the 
side  of  the  carriage. 

A  A  is  the  side  of  the  carriage  ;  B  is  a  metal  tube  fastened 
to  its  inside,  a  spiral  steel  spring  is  contained  in  this  tube,  and 
fastened  to  a  rod  I.     This  rod  has  a  metal  plate  D  on  one  end, 

which  secures  it  at  C, 
A  and  holds  the  spring 

back.  On  the  other 
end  of  the  rod  a  ham- 
mer head  is  fixed. 
When  the  knob  E  is 
pressed,  it  shoves  the 
plate  D  from  its  place, 
when  the  force  of  the 
spring  will  send  for- 
ward   the     hammer. 


b 


bell  F,  placed  on  the 
outside  of  the  carriage, 
would  attract  the  at- 
tention of  the  guard. 
The  hammer  would 
remain  outside,  and  the  carriage  where  assistance  was  wanted 
be  seen  immediately.  If  any  passenger  used  this  "  facetiously," 
the  trick  could  at  once  be  discovered,  as  the  only  part  of  the 
apparatus  under  the  control  of  the  passenger  is  the  knob  on  the 
outside  of  the  panel,  as  shown  at  G,  and  the  spring  could  not 
be  placed  in  its  former  position  except  by  opening  a  small  door 
in  the  panel,  which  would  be  kept  locked. 

2.  In  the  following  plan,  there  would  be  the  necessity  of  the 
guard's  van  being  higher  than  the  other  carriages.  There  are 
other  evident  objections  to  the  details. 


RAIL  WA  YS  AND  LOCOMOTIVES. 


:43 


W 


rrfTi 


m: 


GUARDS 
VAN 


2s: 


rmn 


s 


:s 


By  pulling  the  handle  B  you  not  only  ring  the  bell,  but  also 
raise  the  alarm  signal  C  to  the  position  shown  by  the  dotted 
lines.  In  the  alarm 
signal    there    is    a  Ai;t~T°ite 

piece  of  red  glass, 
on  which  is  painted 
the  number  of  the 
carriage,  which, 
when  raised,  ex- 
actly fits  on  the 
face   of  the    lamp 

D,  thus  showing  a  red  light.  By  this  means  the  guard  would 
be  enabled  to  discover,  either  by  day  or  night,  the  carriage 
from  which  the  signal  is  made. 

3.  Let  every  car- 
riage have  a  loud 
bell  attached,  with 
a  rope  and  handle, 
or  chain  and  han  die 
from     every    com- 
partment, so  that  the  pulling  of  the  handle  would  cause  the  bell 
to   ring,    and  so  attract 
the  guard's  notice.      Let 
the  guard's  van  be  built 
a  little  higher  than  the 
other  carriages,  so  that 
he  could  always  have  a 
full  view  of  the  train,  and 
see  when  all  was  right. 

4.  In  this  scheme  the 
bells  are  done  away  with, 
.  and     explosive     signals 
substituted. 

Fig.  I  is  the  side  view, 
AAAA  are  four  common 
railway  fog  signals ;  each 
one  is  coated,  and  made 
perfectly  air-tight  (glass 
would  answer  the  pur- 
pose best),  so  as  to  pro- 
tect the  powder  from  injury  and  moisture.     These  signals  are 


144 


RAILWAYS  AND  LOCOMOTIVES. 


shaped  as  shown  in  fig.  3,  and  made  about  the  size  of  a  small 
oyster.  BB  represent  the  sides  of  box  in  which  the  signals  A 
are  enclosed.  CC  are  two  square  spouts  or  channels,  leading 
down,  one  to  each  wheel — on  the  side  of  the  carriage,  on  which 
the  machine  is  fixed — as  shown  in  fig.  2.  These  channels  are 
just  large  enough  to  admit  of  the  free  passage  through  them  of 
the  signals  A.  DD  is  a  self-acting  guide,  placed  at  the  junc- 
tion of  the  two  channels  CC,  and  works  on  its  hinge  B.  The 
upper  portion  of  the  guide  DD  is  just  weighty  enough  to  cause 
it  to  rest  in  the  position  seen  in  the  sketch,  or  in  that  of  the 
dotted  line. 

The  lower  part  of  the  guide  is  a  light  square  board  hanging 
beneath  the  flooring  of  the  carriage,  and  is  acted  upon  by  the 

rush  of  air  when  the 
FIC.2.  _^  train    is     in    motion. 

Thus  it  will  be  seen 
that  the  channel  on 
the  right  or  left  hand 
side  will  be  opened  as 
the  direction  of  the 
train  may  require.  F 
consists  of  a  lever, 
slide  and  spring,  the 
working  of  which  will 
shortly  be  explained. 
E  is  a  wire,  and  may 
be  connected  with  or- 
dinary bell  handles  in 
each  compartment  or 
to  each  seat  if  thought 
proper.  The  apparatus  may  be  placed  under  the  seat,  or  any 
part  of  the  floor,  but  is  best  about  midway  between  the  two . 
wheels.  The  box  BB  and  the  channels  CC  may  be  made  of 
thin  sheet  metal. 

The  working  is  as  follows  : — The  bell  handle  G  being 
touched,  the  lever  F  is  operated  upon ;  the  small  slide  N  is 
withdrawn,  thus  releasing  the  bottom  signal  A,  at  the  same 
time  the  spring  M  presses  against  the  second  signal  A,  and 
holds  it  in  its  place  until  the  slide  returns,  when  the  second 
signal  takes  up  the  position  of  the  first.  The  first  signal  A 
being  now  at  liberty,  passes  down  the  left-hand  channel  C,  and 


RAILWAYS  AND  LOCOMOTIVES. 


H^ 


is  delivered  under  the  wheel,  fig.  2,  which  runs  over  it  and 
causes  it  to  explode.  This,  as  in  the  case  of  an  ordinary  fog 
signal,  is  accompanied  by  a  loud  report,  which  would  call  the 
attention  of  the  guard  and  the  whole  train.  In  the  foregoing 
description  the  train  is  supposed  to  be  proceeding  in  the  direc- 
tion of  the  arrow  in  fig.  i.  Should  the  train  be  going  the 
opposite  way,  the  guide  DD  would  be  reversed  by  the  pressure 
of  the  current  of  air  on  the  lower  part  of  it,  and  would  then  lie 
in  the  position  of  the  dotted  line,  thus  opening  the  channel  C 
on  the  right-hand  side,  down  which  the  signal  A  would  slide, 
and  be  dehvered  between  the  wheel  and  the  rail  as  before 
described.  The  alarm  may  be  repeated  as  long  as  there  are 
any  signals  A  in  the  box, 
which  may  be  constructed 
to  contain  any  number. 

One  advantage  to  be 
claimed  for  this  scheme  is 
that  no  connection  between 
one  carriage  and  another, 
along  the  whole  length 
of  the  train,  is  necessaiy 
to  effect  a  communication 
with  the  guard. 

5.  The  following  plan 
suggests  oral  communica- 
tion between  passengers 
and  guard.  It  is  proposed 
to  place  beneath  the  floor 
of  each  carriage  a  metal 
speaking  -  tube,  connected 
between  the  carriages  by  a 
continuation  of  indiarubber 
tubing,  coupled  as  shown 
in  the  annexed  drawing, 
forming  a  Une  of  commu- 
nication between  the  guard 
and  driver  at  either  end  of  the  train.  The  pipe  to  be  supplied 
at  each  end  with  an  alarm  whistle. 

Each  compartment  of  the  carriages  should  be  furnished  with 
an  intercommunicator,  which  would  enable  the  passengers  to 
communicate  with  the  guard  or  driver  through  the  same  pipe. 
Across  the  mouthpiece  in  each  carriage  it  is  also  proposed  to 

K 


146 


RAILWAYS  AND  LOCOMOTIVES. 


place  a  small  clasp,  secured  by  a  seal  (that  must  be  broken 
before  the  apparatus  can  be  used),  which,  by  being  the  means 
of  detection  of,  is  therefore  a  security  against,  improper  use. 

A,  communicator, 
as  seen  in  the  car- 
riage ;  B,  intercom- 
municator  under  the 
floor  of  ditto ;  C, 
screw  coupler  be- 
tween the  carriages. 
To  communicate, 
break  the  seal,  pull 
out  the  pipe  as  far 
as  it  will  come,  and 
hold  it  so  till  your 
communication  is 
complete,  tell  the 
guard  the  number  of 
the  carriage,  then  let 
the  pipe  return  to  its 
place  by  the  action 
of  the  spring. 

Tramway  Loco- 
motives.— The  in- 
troduction of  the 
tramway  in  the  Lon- 
don streets  will  even- 
tually, we  have  no 
doubt,  lead  to  the 
employment  of  the  locomotive  instead  of  horses.  Messrs  Ave- 
ling  &  Porter  have  adapted  one  of  the  road  locomotives  for  a 
tramway  at  Mr  Gray's  Chalk  Works,  Essex,  for  the  purpose  of 
hauling  up  the  excavated  chalk  to  the  docks.  This  engine  we 
now  describe.  On  the  top  of  the  boiler,  easily  accessible,  is 
arranged  the  gearing.  A  pinion  on  the  crank-shaft  gears  into 
a  spur-wheel  on  a  second  shaft,  from  which  motion  is  trans- 
mitted to  the  driving-wheels,  four  in  number,  by  an  endless 
chain.  The  engine  is  often-horse  nominal;  cylinder,  10  in. 
diameter,  12-in.  stroke;  grate  surface  in  fire-box,  7 J  square 
feet ;  number  of  tubes  in  boiler  60,  each  2^  in.  external 
diameter.     There  are  two  feed-water  tanks,  one  under  the  coal 


RAILWAYS  AND  LOCOMOTIVES.  147 

tender,  and  the  other  under  the  front  part  of  the  boiler,  holding 
collectively  350  gallons.  The  wheels  are  4  feet  diameter,  with 
short  tyres,  coupled,  as  shown,  with  an  endless  chain,  which 
can  be  tightened  by  an  apparatus  consisting  of  a  slot  in  the 
main  bracket,  in  which  the  bearings  of  the  shaft  can  be  raised 
and  lowered.  The  cylinder  is  jacketed,  steam  being  carried 
around  it  to  the  valve-chest.  The  boiler  is  fed  by  a  pump 
worked  by  an  eccentric  on  the  crank-shaft.  The  fuel  is  carried 
in  a  coal-bunker  formed  on  the  foot-plate  behind  the  fire-box, 
sufficient  space  being  provided  to  accommodate  from  10  cwt. 
to  20  cwt.  of  coal,  according  to  the  mode  of  packing.  At 
Gray's  the  line  leading  from  the  quarries  to  the  wharves  is  about 
a  mile  in  length,  and  is  laid  to  the  4-ft.  8J-in.  gauge.  At  the 
quarries  it  divides  into  two  branches,  one  having  an  incHne  of 
I  in  36  to  I  in  41  against  the  traffic,  the  incHne  being,  more- 
over, situated  where  the  line  makes  a  series  of  reverse  curves. 
The  other  branch  has  a  steep  incline  where  it  leaves  the  pit. 
On  the  former  branch  the  load  of  the  engine  consists  of  15 
waggons,  weighing  about  i^  tons  each,  and  each  containing  i| 
tons  of  chalk,  the  total  load  being  thus  45  tons,  in  addition  to 
the  weight  of  the  engine.  But  the  engine  can  take  20  loaded 
waggons  up  the  bank,  and  a  still  heavier  load  has  been  hauled. 
On  the  latter  branch  the  load  of  the  engine  consists  of  1 5 
waggons,  weighing  ij  tons  each,  and  each  loaded  with  2I  tons 
of  chalk.  Thus  the  load,  exclusive  of  engine,  is  56 J  tons.  As 
to  economy,  we  learn  that  during  one  week  the  2  engines 
formerly  employed  conveyed  3138  tons  of  material  from  the 
quarries  to  the  wharves,  with  a  consumption  of  141 J  cwt.  of 
coal,  the  fuel  consumed  being  thus  equal  to  5  lbs.  per  ton  drawn. 
On  the  other  hand,  two  of  Messrs  Aveling  &  Porter's  engines 
transported  during  corresponding  week  5  1 00  tons  of  material, 
with  a  consumption  of  125  cwt.  of  coal,  the  expenditure  of  fuel 
being  in  this  case  equal  to  about  2^  lbs.  of  coal  per  ton  hauled. 
It  is  estimated  that  this  difference  in  the  quantity  of  coal  required 
to  perform  a  given  work  will  save  the  company  upwards  of  ^260 
per  annum.  Altogether,  these  engines  have  given  abundant 
evidence  of  being  well  adapted  for  use  in  quarries,  and  wherever 
heavy  loads  have  to  be  moved  at  slow  speeds — doing  the  work 
at  about  half  the  cost  of  horse-power.  The  engines  can  also  be 
employed  to  drive  portable  or  fixed  machinery.  All  the  wheels 
being  coupled,  the  whole  weight  is  available  for  producing  adhesion 
to  the  rails,  which  is  sufficient  for  the  requirements  of  such  lines. 


148 


FIREARMS. 


Wheel  Grease. — Nothing  is  equal  to  tallow  for  large  cog- 
wheels ;  but  a  good  grease  may  be  made  of  tallow  25  pounds, 
tar  25  pounds,  soda  1 5  pounds,  and  water  3  or  4  gallons.  Boil 
the  soda  and  water  till  the  former  is  dissolved,  then  add  the 
other  ingredients,  and  boil  till  thoroughly  mixed. 

Rifle  Stadia  for  Judging  Distances. — An  apparatus  of  the 
kind,  for  rifle  practice,  patented  by  Mr  D.  M 'Galium,  has  been 
approved  and  extensively  used  in  some  districts. 

1.  Place  the  butt  of 
the  rifle  on  the  ground, 
with  the  toe  of  it  to- 
wards the  right. 

2.  Then  place  the 
piece  of  metal  in  muzzle 
with  end  marked  '  Foot' 
upwards,  if  the  distance 
of  a  man  be  required. 

3.  If  the  distance  of 
a  man  on  horseback  be 
required,  place  the  end 
marked  '  Horse '  up- 
wards. 

4.  Steady  rifle  with  left  hand,  and  with  the  finger  and  thumb 
of  the  other  hold  the  tape  closely  to  the  eye  on  the  cheek-bone. 

5.  Then  look  at  the  object  through  the 
aperture,  and  slide  the  face  along  the  tape 
until  the  eye  definitely  and  completely 
covers  the  feet  of  the  man  and  the  top  of 
his  cap,  or  the  hoof  of  the  horse  and  the  cap 
of  its  rider. 

6.  Now  observe  the  mark  on  the  tape 
where  the  finger  is,  and  it  will  show  the 
number  of  yards  distant.  Thus  :  Should  the 
finger  appear  at  the  first  subdivision  beyond 
100,  the  distance  would  be  iio;  if  at  the 
second  subdivision,  it  would  be  1 20  yards,  &c. 

7.  Should  the  object  be  more  than  350 
yards  off,  it  will  be  necessary  to  screw  the 
ramrod  in  the  centre  of  the  piece  of  metal, 

and  steady  the  rifle  with  the  ramrod  by  holding  it  securely 
and  keeping  the  tape  at  its  full  tension  ;  then  proceed  as  before. 


900  yards. 


[oo  yards. 


FIREARMS.  149 


Gun  Cotton. — The  following  is  stated  to  be  the  best  and 
simplest  process  for  making  gun  cotton.  Saturate  some  cotton 
wool  in  a  solution  of  equal  volumes  of  the  strongest  oil  of 
vitriol  and  nitric  acid  for  a  few  minutes,  then  express  the 
superabundant  liquid  out  of  the  cotton,  and  wash  it  in  cold 
water  until  all  taste  of  acidity  has  gone  ;  lastly,  dry  at  a  gentle 
heat,  about  120°  or  130". 

Force  of  Gunpowder. — When  gunpowder  is  heated  nearly 
up  to  the  point  of  decomposition,  previously  to  ignition,  the 
force  of  its  explosion  is  greatly  increased.  It  is  stated  that  a 
temperature  of  160°  Fahr.  increases  the  force  of  the  explosion 
I -5th,  while  a  temperature  of  400°  nearly  doubles  it.  This 
may  in  some  measure  account  for  the  fact  that  highly-heated 
guns  are  liable  to  burst  if  the  charge  has  been  allowed  to 
remain  in  the  chamber  a  sufficient  time  before  firing. 

Gun  Barrels. — To  Bore. — Take  a  piece  of  rod,  cast  steel, 
I"  in.  smaller  than  the  interior  of  the  barrel  and  a  few  inches 
longer,  beat  one  end  up  something  larger  than  the  size  of  bore, 
then  turn  or  file  it  the  shape  of  an  egg,  leaving  the  swell  or 
centring  part  i-2oth  of  an  inch  larger  than  the  bore.  With 
a  saw-file,  cut  longitudinal  cuts  \  in.  apart,  laying  them  the 
same  angle  as  a  rose-bit  countersink,  taking  care  not  to  injure 
the  periphery  of  the  tool ;   harden,  and  temper  to  straw  colour. 

Siai7iing. — Spirits  of  wine  i  oz.,  tincture  of  steel  i  oz., 
muriate  of  mercury  \  oz.,  nitric  acid  \  oz.,  and  water  i  quart. 
The  above  mixture  must  be  well  incorporated  before  use. 
Process. —  i.  The  grease  to  be  removed  by  coating  the  gun 
with  lime,  put  on  in  a  thin  paste,  and  allowed  to  dry,  then 
brushed  off  with  a  clean  hard  brush.  2.  The  mixture  to  be 
laid  evenly  on  the  gun  with  a  sponge,  and  allowed  to  stand  till 
dry.  This  operation  to  be  repeated  as  frequently  as  the  gun 
dries,  for  the  first  ten  hours,  then  the  rust  to  be  thoroughly 
scratched  off  with  wire  cord.  3.  Coat  with  mixture,  and  let 
it  stand  till  dry  ;  if  the  gun  rusts  freely,  no  more  mixture  need 
be  applied,  but  that  already  applied  may  be  scratched  off  with 
wire  cord  at  the  end  of  ten  hours  if  dry  ;  but  if  it  should  rust 
slowly,  then  one  or  two  extra  coatings  of  the  mixture  may  be 
laid  within  the  ten  hours,  taking  care  that  the  old  rust  is  dry 
before  again  applying  the  mixture.  4.  As  soon  as  the  barrel 
is  dark  enough,  it  must  be  immersed  in  boiling  water  to  kill 


HOROLOGY. 


the  acid,  and  then  oiled  with  olive  oil  while  warm ;  then  remove 
the  oil  with  turpentine,  and  varnish  with  copal  varnish. 

Browning. — Equal  parts  of  butter  of  antimony  and  olive  oil 
to  be  rubbed  on  while  the  barrel  is  hot,  expose  to  the  air  till 
sufficiently  brown,  clean  carefully,  and  coat  with  a  thin  shellac 
varnish.  Butter  of  antimony  is  a  powerfully  corrosive  poison, 
and  must  therefore  be  handled  with  care. 

Colouring. — First  clean  the  barrel  perfectly,  but  do  not  touch 
it  with  the  hands.  To  avoid  this,  put  a  stick  or  plug  into  the 
end  of  the  barrel  to  hold  it  with,  then  apply  the  following  mix- 
ture with  a  rag  (not  too  much  at  a  time,  if  a  twisted  barrel,  as 
you  will  not  be  able  to  get  the  twist  to  show  properly).  After 
the  colour-matter  gets  dry,  it  must  be  rubbed  off  with  a  steel- 
wire  brush.  For  a  plain  barrel — \  oz.  nitric  acid,  |-  oz.  spirits 
of  nitre,  2  oz.  sulphate  of  copper,  i  oz.  tincture  of  steel,  8  gills 
of  water.  For  a  twisted  barrel — \  oz.  spirits  of  nitre,  \  oz. 
tincture  of  steel,  \  oz.  sulphate  of  copper,  1 5  grains  of  mercury, 
|-  pint  of  water.  After  having  stained  the  barrel  apply  the 
following  polish  : — 2  oz.  spirits  of  wine,  \  oz.  gum  Benjamin. 
Put  it  on  with  a  soft  rag  or  camel-hair  brush  :  use  it  quickly, 
or  it  will  dry  very  fast. 

Tlie  Verge  Escapement. — Every  one  who  wears  a  watch 
should  know  something  of  its  mechanism.  He  would  then  be 
better  enabled  to  take  care  of  it,  and  sef  it  right  when  it  went 
wrong.  There  are  three  kinds  of  escapements  used  in  modern 
watches — the  Verge,  the  Horizontal,  and  the  Lever.  The  first 
is  the  oldest,  and  in  some  few  respects  the  best.  The  parts 
of  a  verge  are  the  cock  and  foot  pallets,  also  cock  and  foot 
pivots,  and  the  "  collet,"  or  piece  of  brass  soldered  on  to  the 
top,  and  to  which  the  balance  is  riveted.  The  parts  of  a  pinion 
are  the  leaves  or  head,  the  arbor,  and  the  pivots  or  bearings. 
The  parts  of  a  wheel  are  the  teeth,  the  rim,  and  the  cross  ;  if 
the  wheel  is  not  riveted  on  to  the  head  of  a  pinion,  a  "  collet " 
is  driven  on  to  the  arbor,  and  to  w^hich  the  wheel  is  riveted. 
The  escapement  is  the  term  used  to  illustrate  the  action  of  the 
pallets  in  connection  with  the  last  or  scape  wheel,  one  tooth  of 
which  escapes  at  each  vibration  of  the  balance.  The  crown- 
wheel or  verge  escapement  was  the  first  invented.  Fig.  i 
shows  how  it  is  arranged  in  a  watch.  B  is  the  balance,  the 
axis  of  which  is  the  verge ;   P'^  is  the  cock  pallet,  and  P  is  the 


HOROLOGY. 


153 


!    - 

1 L 

1 — 1 

r 

'  S 

^ 

=1 

P' 



M        ! 

1       1         ! 

\^ 

ll     M      11    1 

-^^^ 

0(lnrt 

1 

N   1 
P 

li    II    Hi 

i_j 

^1 

h° 

X 

foot  pallet ;  the  top  or  cock  pivot  runs  in  the  cock  C,  and  the 
bottom  or  foot  pivot  in  the  potance  X.  S  is  the  hair-spring 
and  stud.  The  scape-wheel  O,  also  called  the  balance-wheel, 
is  riveted  on  to  the  head  of  the  pinion  ;  the  pivot  inside  the 
wheel  runs  in  a  dovetail  fitted  into  the  nose  of  the  potance  at 
N,  this  dovetail  is  made  to  slide  in  and  out,  so  as  to  get  the 
hole  opposite  the  body  of  the  verge,  or  the  escapement  equal ; 
the  pivot  at  the  other 

end  of  the  pinion  runs  fig  .  1  . 

in  a  hole  in  the  follower 
F,  which  is  fitted  into 
the  counter  -  potance. 
The  contrate- wheel  W 
is  not  riveted  on  the 
pinion,  but  has  a  "  col- 
let "  on  the  arbor  to 
enable  it  to  work  into 
the  scape-pinion.      The 

teeth  and  rim  are  contrary  to  those  of  other  wheels,  whence  it 
takes  its  name.  Fig.  2  shows  the  details.  X  is  the  potance  ; 
T  is  the  counter-potance,  which  is  riveted  into  the  top  plate, 
and  into  the  hole  of  which  the  follower  F  is  fitted  ;  V  is  the 
verge  with  the  "  collet "  turned  down  to  fit  the  balance  ;  Z  is 
the  hair-spring  ''collet;"  B  is  the  balance;  S  is  the  hair- 
spring stud,  the  outer  coil  of  the  hair-spring  is  pinned  into 
the  stud,  and  the 
inner  coil  is  pinned 
into  the  "  collet," 
which  fits  spring- 
tight  on  to  the 
verge  collet  and 
close  up  to  the 
balance,  and  can 
be  set  to  any  place 
by  turning  it  round 
on  the  vers^e  with  a 


^ 


screw-driver  put  into  the  notch  ;  D  is  the  regulator,  fitted  into, 
a  slide  so  that  it  can  move  in  a  circle  having  the  verge  as  a 
centre,  the  end  of  the  regulator  projects  under  the  outer  coil  of 
the  spring,  and  has  two  small  pins  rising  up  from  it,  and 
between  which  the  spring  plays.  The  effective  length  of  the 
spring  can  thus  be  altered  by  moving  the  index  to  fast  if  the 


J52 


HOROLOGY. 


watch  loses,  and  to  slow  if  it  gains.  If  the  regulator  is  at  fast 
or  slow,  and  the  watch  continues  to  gain  or  lose,  the  spring 
must  be  altered  from  the  stud,  that  is,  more  spring  let  out  if 
gaining,  and  if  losing  more  spring  taken  up.  To  do  this,  put 
a  bristle  into  the  cross  of  the  contrate-wheel  to  prevent  it  run- 
ning down  ;  then  take  off  the  cock  C  ( Fig.  i )  and  unpin  the 
spring  out  of  the  stud  with  a  pair  of  tweezers,  take  out  the 
verge  and  turn  the  collet  round  with  a  screw-driver  in  the 
direction  to  bring  more  or  less  spring  through  the  stud  as  the 
case  requires  ;  having  done  this,  replace  the  verge,  join  in  the 
spring,  and  put  on  the  cock  again.    Then  try  if  the  watch  is  in 

beat;  thus,  suppos- 
ing the  balance  is  at 
rest  and  the  banking 
pin  at  B,  if  the  con- 
trate-wheel is  pushed 
round  slowly  and 
steadily  with  the 
thumb,  the  pin  will 
be  drawn  first  to  A 
and  then  to  C  if  the 
watch  is  in  beat ; 
if  it  is  not,  the 
"draw"  will  be  more 
to  one  side  than  the 
other ;  if  C  has  most 
draw  the  spring  must 
be  let  out  a  little, 
and  if  A  has  most 
the  spring  must  be 
taken  up  a  little. 
We  must  now  ex- 
plain the  action  of  the  escapement.  The  verge  pallets  are 
nearly  at  right  angles  ;  the  scape-wheel  has  always  an  odd 
number  of  teeth,  so  that  a  tooth  on  one  side  is  opposite  a  space 
on  the  other,  and  when  one  pallet  is  in  action  the  other  is  out 
of  action.  Fig.  3  is  a  sketch  of  two  escapements,  the  teeth  of 
the  wheel  and  the  pallets  are  enlarged.  The  wheel  must  be 
supposed  to  be  turning  on  its  axis  with  the  teeth  i  and  2,  and 
the  cock-pallets  P'  P'  at  the  top,  and  the  dotted  teeth  and  the 
foot-pallets  P  P  at  the  bottom.  Tooth  i  has  just  escaped  from 
and  given  impulse  to  the  pallet  P',  and  the  dotted  tooth  has 


F  1  a     ^ 


HOROLOGY.  153 


dropped  on  to  the  pallet  P,  the  balance  B  is  "  vibrating "  or 
turning  in  the  direction  of  the  arrow,  and  will  continue  to  do 
so  until  the  impulse  is  exhausted  by  the  bending  up  of  the  hair- 
spring and  the  "  recoil"  or  backward  movement  of  the  wheel 
produced  by  the  dotted  tooth  opposing  the  pallet  P  ;  the  balance 
will  now  be  brought  back  by  the  tension  of  the  hair-spring  ;  the 
dotted  tooth  will  then  give  impulse  to  and  escape  from  pallet 
P,  the  next  tooth  dropping  on  to  pallet  P^,  as  shown  by  tooth 
2  ;   the  balance  B'  is  vibrating  in  the  direction  of  the  arrow, 
tooth  2,  opposing  pallet  P^,  producing  the  recoil  as  before.      It 
will  thus  be  seen  that  two  contrary  vibrations  of  the  balance 
take  place  before  a  tooth  has  completely  escaped.     The  bank- 
ing is  to  prevent  the  balance  turning  round  too  far,  in  which 
case  the  pallet  would  be  turned  away  from  the  wheel,  which 
would  of  course  run  down  with  great  force,  and  break  its  teeth 
by  striking  against  the  pallets  when  they  turned  round  again. 
The  best  banking  is  a  pin  in  the  balance  at  B,  and  therefore 
moving  in  a  circle  round  the  edge  of  the  cock  C,  fig.  i,  which 
covers  the  balance.      The  extent  of  the  banking  is  determined 
by  the  pin  meeting  two  projecting  parts  of  the  cock  which 
reach  beyond  the  circle  the  banking-pin  moves  in.     The  bank- 
ings are  made  as  wide  as  possible,  and  for  the  teeth  to  have  a 
fair  hold  on  to  the  pallets.     Thus,  supposing  the  banking-pin 
is  turned  by  an  accidental  jerk  to  B,  fig.  4,  the  dotted  tooth  i 
will  act  on  pallet  P,  and  bring  the  balance  round  again  ;   and 
if  the  banking-pin  is  at  B^,  the  tooth  2  will  act  on  pallet  P% 
and  bring  the  pallets  into  action  again.      The  great  defect  in 
the  verge  escapement  is  the  "  recoil,"  the  wheels  being  carried 
half  as  far  back  as  they  have  advanced,  consequently  the  verge 
and   dovetail   holes  wear  very  wide,  and  when  so  worn  the 
L      watch  cannot  go  well ;   the  constant  rubbing  of  the  wheel-teeth 
wt     on  the  pallets  wears  the  verge  out,  and  also  the  tops  off  the 
■     wheel-teeth,  not  all  alike,  but.  very  irregular  ;  hence  the  wheel 
ft.  often  requires  topping  or  recutting.     The  nose  of  the  potance 
K    must  be  filed  to  let  the  wheel  up  closer,  and  then  the  counter- 
H  '  potance  filed  away  to  let  the  follower  up,  or,  what  is  much  better, 
B     a  new  follower  must  be  made.     The  verge  escapement  could  be 
Bt  constructed  much  better,  but  as  it  is  now  nearly  superseded  by 
^Bthe  lever  escapement,  no  improvements  are  likely  to  be  adopted  ; 
^"^but  as  there  are  a  great  many  verge  watches  in  use,  a  knowledge 
of  the  escapement  is  still  required  to  keep  them  in  repair. 


154 


HOROLOGY. 


Four-Legged  Clock  Escapement. — The  following  are  the 
particulars  of  Mr  Denison's  Four-legged  Gravity  Escapement 
for  regulating  clocks  : — 

Fig.  I  is  a  view  of  the  escapement,  looking  at  the  back  of 
the  clock.  Fig.  2  is  a  section  of  the  escapement  and  part  of 
the  train  of  wheelwork.     The  letters  refer  to  the  same  parts  in 

both  figures.  EF  is  the  scape- 
wheel  of  a  diameter  of  three 
inches,  the  acting  faces  of  the 
four  teeth  being  at  right  angles 
to  each  adjacent  one.  On  the 
central  disc  of  the  scape-wheel 
are  set  eight  pins,  four  pointing 
one  way  and  four  the  other. 
These  pins  are  \  of  an  inch 
from  the  centre  of  the  wheel, 
and  one  set  of  four  are  to  be 
placed  on  a  line  with  the  act- 
ing faces  of  the  teeth,  and  the 
remaining  four  equidistant  be- 
tween them. 

A,B,C,D  are  the  pallets  which 
are  lifted  by  the  pins  of  the 
scape- wheel  acting  on  the  arms 
LM.  The  stops  on  the  pal- 
lets are  shown  at  GH,  and  the 
proper  placing  them  requires 
a  little  attention.  In  drawing 
out  the  escapement,  the  scape- 
wheel  should  be  placed  within 
both  as  at  E,  and  the  next 
look  will  show  the  proper 
place  for  the  stop  H  to  be 
screwed  to  the  pallet  CD. 
The  stop  G  must  be  placed 
a  little  higher  than  the  stop 
H.  The  distance  of  the  pallet 
arbors  from  the  scape- wheel  centre-  is  3*5  inches,  the  arbors 
being  placed  as  near  the  vertical  line  as  possible,  to  avoid  fric- 
tion. The  pallets  are  prolonged  until  they  meet  the  pendulum- 
rod    as  shown  at  B  and  D.      The  whole  of  this  escapement 


1 


HOROLOGY.  155 


should  be  made  of  steel.  The  weight  of  the  pallets  tnust  be 
made  such  as  to  cause  the  pendulum  to  swing  an  arc  of  4  de- 
grees. A  very  material  feature  in  this  escapement  is  the  fly 
IK,  which  is  attached  to  the  scape-wheel  arbor  by  a  piece  of 
watch-spring  in  the  usual  manner.  The  object  of  this  is  to 
prevent  what  is  called  tripping,  that  is,  the  pallets  A,  B,  C,  D 
being  thrown  out  too  far  by  the  scape-wheel  turning  too  quickly. 
The  fly  is  large,  measuring  in  total  length  4  in.  by  i  in.  broad." 
It  will  be  seen  by  fig.  2  that  the  pallets  are  not  in  the  same 
plane,  but  that  the  scape-wheel  turns  between  them.  One  stop 
is  placed  on  the  front  of  one  pallet,  and  the  other  on  the  back 
of  the  other  pallet.  We  will  note  the  numbers  of  the  teeth  of 
the  wheels  and  pinions,  which  will,  we  think,  be  found  most 
desirable. 

Wheel  No.  i.  120  teeth  drives  pinion  of  10  teeth  or  leaves. 

„  2.  80  ,,  10  ,, 

„  3.  IS  „  10 

4.  75  „  10 

The  great  wheel  No.  i  had  better  be  at  least  f  of  an  inch 
broad  on  the  edge,  because  these  clocks  take  a  heavier  weight, 
about  25  lbs.,  for  a  regulator.  These  clocks  have  only  been 
made  with  second  pendulums  so  far  as  we  know,  and  it  may 
be  convenient  to  state  the  times  of  revolution  of  the  various 
wheels. 

The  scape-wheel  turns  once  in  8  seconds. 
Wheel  No.  4  „  60  seconds. 

,,  3  „  7j  minutes. 

„  2  „  I  hour. 

„  I  ,,  12  hours. 

It  is  perhaps  hardly  necessary  to  remark  that  the  acting  sur- 
faces of  the  various  parts  of  the  escapement  must  be  left  as 
hard  as  they  safely  can  be.  It  is  essential  that  the  fork-pins 
of  the  pallets  B  and  D  should  be  so  adjusted,  that  as  the  pen- 
dulum-rod comes  into  contact  with  one  it  just  leaves  the  other. 
For  the  reason  of  this,  and  for  a  great  variety  of  information 
respecting  gravity  escapement,  we  refer  our  readers  to  Mr 
Denison's  book,  certainly  one  of  the  most  scientific  and  valuable 
yet  produced  on  its  special  subject. 

But  for  the  information  of  those  to  whom  the  book  is  not 


156 


HOROLOGY. 


accessible,  we  may  explain  the  action  of  the  escapement.  At 
present  one  leg  of  the  scape- wheel  is  resting  on  the  stop  H  ; 
the  pendulum  P  is  swinging,  as  shown  by  the  arrow,  to  the 

right,  and  will 
carry  with  it  the 
pallet  CD.  As 
soon  as  the  stop 
H  is  lifted  out  of 
the  way  of  the 
scapewheel  tooth, 
the  wheel  acted 
on  by  the  clock- 
weight  will  turn 
until  the  tooth  N 
is  arrested  by  the 
stop  G,  and  dur- 
ing this  motion  of 
the  scape -wheel 
the  pallet  AB  will 
be  lifted  by  the 
pin  in  the  scape- 
wheel  a  little  out- 
wards to  the  left, 
and  it  is  by  the 
weight  of  the 
pallet  AB  acting 
through  the  fork- 
pin  at  B  onthe  pen- 
dulum -  rod  from 
that  point  towhich 
the  pallet  is  lifted 
by  the  scapewheel 
to  that  pointwhere 
the  pendulum 
leaves  it  that  half 
the  impulse  to  the 
pendulum  is  sup- 
plied. The  pallet 
CD  on  the  other  side  contributes  the  other  half  in  a  similar 
manner.  It  will  be  observed  from  fig.  2  that  the  great  wheel 
No.  I,  on  the  arbor  of  which  is  placed  the  barrel  for  the  weight 


I 


HOROLOGY.  157 


cord,  is  at  the  top  of  the  frame.  This  arrangement  was  almost 
unavoidable  with  some  of  the  early  forms  of  the  gravity  escape- 
ment, but  it  will  be  much  more  desirable  to  have  the  great 
wheel  at  the  bottom  of  the  frame,  and  with  this  form  of  the 
escapement  there  is  no  difficulty  about  it.  We  recommend 
any  one  before  commencing  the  actual  construction  to  make 
fair  working  drawings  of  the  clock. 

Compensating  Pendulum. — The  follow- 
ing is  suggested  by  a  practical  watchmaker  as 
a  good  plan  for  a  compensation  pendulum.      C^ 

1  is  the  back  cock  attached  to  the  clock  frame. 

2  to  4  is  the  pendulum-rod  of  flat  iron,  the 
middle  rod  riveted  fast  to  it  at  4,  and  the 
outside  rod  riveted  to  the  middle  one  at  5. 

3  is  the  crutch  that  works  the  pendulum. 
6  is  a  screw  fast  to  the  pendulum-rod  to 
steady  the  middle  rod,  but  loose  in  the 
middle  rod  to  allow  it  to  expand.  7  is  a 
screw  fast  to  the  middle  rod  to  steady  the 
outside  rod,  but  loose  on  outside  to  allow  it 
to  expand.  8  is  the  pendulum  ball  of  iron 
on  the  outside  rod.     As   the  rod  from  2  to 

4  expands  downwards,  the  middle  rod  from 


fll. 


4  to  5  expands  upwards,  and  keeps  the  pen-  ^Uf 

dulum-ball  in  the  same  position. 

The  Chronometer  Escapement. — The  chronometer  escape- 
ment is  undoubtedly  the  best  timekeeper,  the  reasons  for  which 
are — i.  The  "  impulse  "  is  given  to  the  balance  "  directly  "  by 
the  scape-wheel  without  the  intervention  of  a  lever  or  other 
obstructing  mechanism.  2.  The  impulse  is  given  in  the  most 
favourable  manner,  ''  across  the  line  of  centres,"  and  will  thus 
carry  a  heavier  balance.  3.  The  escapement  is  more  completely 
detached,  hence  the  isochronism  of  the  balance  vibrations  are 
not  as  much  disturbed.  The  chronometer  escapement  is  thus 
admirably  suited  for  marine  timekeepers,  or  box  chronometers, 
as  they  are  called,  and  which  are  hung  in  gimbals  in  a  square 
box  like  a  mariner's  compass.  The  dial  is  thus  kept  always 
horizontal,  and  the  balance  is  also  kept  in  one  position,  that  is, 
working  on  the  cock  pivot.  The  movement  is  also  kept  very 
steady. 


158  HOROLOGY, 


The  case  is  very  different  with  a  pocket-watch,  which  has  to 
go  in  every  position,  lying  up  or  lying  down,  and  is  also  sub- 
jected to  jerks  and  shakes  by  the  most  careful  wearer  in  pulling 
it  out  of  the  pocket  to  see  the  time,  to  say  nothing  of  the  shakes 
and  changes  of  position  while  it  is  in  the  pocket,  and  the  treat- 
ment it  may  get  from  a  careless  wearer.  A  chronometer 
escapement,  therefore,  with  its  heavy  balance,  is  not  suited  for 
a  pocket-watch.  Another  objection  is  that  the  impulse  is  given 
in  the  one  direction  only,  the  unlocking  taking  place  on  the 
return  vibration,  which  receives  no  impulse  ;  hence  if  the  watch 
gets  a  sudden  shake  in  a  contrary  direction  to  the  way  the 
balance  is  vibrating,  the  unlocking  will  be  prevented,  and  the 
watch  will  stop,  and  will  require  a  good  shake  to  start  it  again, 
and  also  if  it  is  let  run  down  must  be  shook  after  winding  to 
start  it.  The  escapement  also  requires  great  accuracy  of  con- 
struction, and  is  otherwise  unsuited  for  rough  use. 

In  the  lever  escapement  the  impulse  is  given  at  every  vibra- 
tion by  the  scape-wheel  to  the  lever,  and  by  the  lever  to  the 
balance.  If  the  escapement  is  made  in  the  proportions  it  will 
not  "  set,"  hence  will  not  be  affected  materially  by  a  sudden 
shake,  neither  will  it  require  to  be  shook  to  start  it  on  winding 
it  up  after  being  run  down.  The  ordinary  lever  escapement 
does  not  require  such  extreme  accuracy  of  construction,  and  is 
therefore  cheaper  and  better  suited  for  rough  use,  and  will  keep 
time  to  within  a  minute  a  week,  which  is  near  enough. 

The  two-pin  lever  escapement  is  considered  the  best  form  of 
lever  escapement,  but  it  is  thought  by  many  to  be  not  so  good 
as  a  timekeeper. 

A  watch,  like  a  steam  engine,  must  be  kept  in  good  order. 
A  steam  engine  cannot  be  let  run  long  without  oil,  but  will 
report  its  sure  wants  in  a  manner  "  not  to  be  mistaken,"  and 
a  labourer  using  a  wheelbarrow  must  for  his  own  comfort 
attend  to  the  ''  screeching  "  of  the  wheel.  The  trains  given  to 
lever  and  other  good  watches  showing  seconds  are  14,400, 
16,200,  or  80,000  vibrations  or  beats  in  an  hour:  each 
"vibration"  means  a  "revolution"  of  the  balance.  Now, 
either  of  these  sums  x  24  x  365  will  give  the  number  of  beats 
or  work  done  in  a  year.  The  slowest — 14,000 — gives 
126,144,000  beats  in  a  year.  A  moment's  attention  to  this 
fact  will  convince  readers  that,  although  the  oil  used  for 
watches  is  the  best  we  can  get,  and  may  not  congeal,  yet  it 


HOROLOGY.  159 


must  be  all  used  up  in  a  year  or  eighteen  months  ;  and  then 
if  the  mainspring  and  great  wheels  are  powerful  enough  to 
keep  the  watch  going,  the  pivots  and  other  actional  parts  must 
and  will  wear  out — in  silence,  of  course,  for  watches  do  not 
"  screech  "  like  wheelbarrows. 

Double-Roller  Escapement. — The  lever-watch  double-roller 
escapement  is  very  similar  to  the  ordinary  kind  of  lever  escape- 
ment with  the  table-roller,  but  may  be  distinguished  by  its 
having  an  additional,  though  small,  roller  below  that  which 
holds  the  ruby-pin.  The  ruby-pin  is  fixed  in  the  main-roller 
in  the  usual  way,  and  serves  the  same  office  as  that  generally 
known  ;  but  as  the  guard-pin  has  no  connection  with  it,  the 
piece  carrying  the  ruby-pin  is  frequently  formed  of  the  shape 
-of  an  arm,  the  steel  disc  being  for  the  most  part  filed  away, 
leaving  only  sufficient  to  secure  it  to  the  balance-staff,  and  to 
hold  the  ruby-pin.  Thus,  then,  this  part  might  be  called  an 
arm,  carrying  the  ruby- 
pin.      Underneath  this  is  All 

■fixed  another  roller,  rather  ry 

small,     having    a    hollow       ZT 


8  v///////////////y//Ay/////^^.v\ 


5 


3 


filed   out   similar   to   that 

which  is  generally  noticed 

in  the  ordinary  table-roller, 

the  object  of  which  is  to 

allow    the    guardpiece   to 

pass  as  the  passing  hollow 

in  the  table-roller  admits  the  passing  of  the  upright  guard-pin 

in  the  lever.     Looking  at  the  two  rollers  together  when  properly 

fixed,  a  person  acquainted  with  the  crank-roller  might  think  that 

one  and  the  same  object  only  was  achieved  ;   but  it  is  not  so. 

Without  referring  to  the  crank-roller  further,  let  it  be  under- 
stood that  the  only  purpose  of  the  second-roller  in  the  double- 
roller  escapement  is  to  serve  the  purpose  of  the  safety  action. 
This  is  accomplished  by  having  a  pin  bent  at  right  angles  from 
the  under  side  of  the  lever,  so  as  to  reach  sufficiently  far  to 
ensure  a  sound  guard-pin  depth.  So  that,  in  reality,  the  main- 
roller  is  a  radial  arm  carrying  the  ruby-pin  ;  then  to  secure  a 
sound  guard-pin  depth  the  small  roller  is  placed  below,  and  the 
bent  guard-pin  projects  sufficiently  long  to  ensure  safety  of  the 
escapement. 


i6o  HOROLOGY. 


The  annexed  diagram  will  assist  in  the  description  : — A, 
main-roller,  carrying  the  ruby-pin  ;  B,  the  lever  ;  C,  the  bent 
guard-pin  \  D,  the  second  or  safety  roller.  The  balance-staff, 
of  course,  passes  through  both. 

To  Restore  Watcli  Dials. — If  the  dial  be  painted,  clean 
the  figures  off  with  spirit  of  wine,  or  anything  else  that  will 
render  the  dial  perfectly  clean  ;  then  heat  it  to  a  bright  red 
heat,  and  plunge  it  into  a  strong  solution  of  cyanide  of  potas- 
sium ;  then  wash  in  soap  and  water,  and  dry  in  box-dust. 
Repeat  if  not  a  good  colour.  Indian  ink  ground  with  gum- 
water  will  do  for  the  figures. 

Blight's  Perpetual  Motion  Electric  Clocks. — Several  of 
these  clocks  have  been  in  use  for  four  or  five  years  without 
intermission.  An  account  of  them  will,  therefore,  be  interest- 
ing. Presuming  that  our  readers  are  acquainted  with  the 
general  principle  of  electric  clocks,  the  following  account  will 
be  understood  by  referring  to  the  engravings  : — In  fig.  i  WW 
are  the  wires  leading  to  the  two  poles  of  the  battery.  The 
wire  W  is  attached  to  the  bracket  b,  and  the  current  passes 
down  the  suspension  of  the  pendulum,  and  by  a  wire,  shown 
by  a  dotted  line,  down  the  wooden  stem  of  the  pendulum,  then 
round  the  coil  of  wire  in  the  bob  of  the  pendulum,  and  up  the 
wire  on  the  other  side,  also  shown  by  a  dotted  line,  to  the 
touching-plate  P,  and  through  the  leg  L  of  the  brake,  and  off 
by  the  wire  W  to  the  other  pole  of  the  battery,  thus  completing 
the   circuit  when  the  pendulum  is  in  the  position  shown  in 

fig.  I. 

The  bob  of  the  pendulum  is  thus  for  the  instant  converted 
into  an  electro-magnet.  The  tube  M  is  fixed  to  the  clock-case, 
and  contains  permanent  magnets,  which  of  course  attract  the 
electro-magnet  in  the  bob  of  the  pendulum,  which  thus  receives 
a  little  additional  impulse  at  every  alternate  stroke.  By  the 
time  the  pendulum  arrives  at  the  other  side,  as  in  fig.  2,  it  has 
in  its  journey  moved  the  break  B,  so  that  the  little  balance- 
weight  T  has  fallen  a  little  past  the  centre  on  the  other  side, 
and  so  has  brought  the  leg  L^  in  contact  with  the  piece  ojf 
glass  G  on  the  stem  of  the  pendulum,  and  has  thrown  the  leg 
L  clear  of  the  touching-plate  P,  and  has  thus  broken  the  cir- 
cuit. The  pendulum  then  makes  the  return  stroke  by  its  own 
weight,  when  contact  is  again  made,  and  so  on. 


HOROLOGY. 


[6i 


By  fitting  a  double  break  to  the  pendulum  it  receives  an 
impulse  at  every  stroke,  instead  of  every  alternate  stroke. 

It  will  be  observed  that  the  break  consists  of  the  two  long 
copper  legs  L,  L",  and  the  balance-weight  T,  all  mounted  on  a 
triangular  piece  of  ivory  which  moves  on  the  pivot  p.  The 
friction  of  moving  this  break  is  obviously  very  httle  ;  it  is,  in 
fact,    so    httle  that 

one    piece    of   zinc  FiC3  Ficz 

and  one  piece  of 
coke  buried  in  the 
ground  afford  a  cur- 
rent of  electricity 
sufficient  to  drive 
eight  or  ten  or  more 
of  these  clocks  for 
a  lifetime. 

Another  feature 
in  this  break  is  that 
the  legs  move  in  an 
arc  of  a  different 
radius  from  that  in 
which  the  contact- 
plates  move;  conse- 
quentlyat  each  time 
of  touching,  the  con- 
tact -  plate  receives 
a  slight  rub,  which 
wipes  off  any  dust, 
and  ensures  a  per- 
fect contact. 

The  wires  W  and 
W% '  on  their  way 
to  the  poles  of  the 

battery,  may  communicate  with  and  work  other  clock-dials. 
These  affiliated  clocks  are  by  preference  made  with  pendulums, 
because  if  the  current  misses  its  errand  once  or  twice,  no  harm 
is  done,  as  each  pendulum  has  sufficient  momentum  to  work 
its  own  clock  for  three  minutes  without  assistance  from  the 
battery. 

In  the  Continental  system  of  electric  clocks  the  affiliated 
clocks  have  no  pendulums,  but  are  actuated  by  a  powerful  cur- 

L 


[62 


HOROLOGY. 


rent  from  an  acid  battery  once  in  a  minute.     Thus,  if  by  any 
mischance  a  clock  "  misses  a  peg"  it  is  a  minute  slow  at  once. 

Under  Mr  Bright's  system  the 
pendulums  of  all  clocks  in  con- 
nection are  vibrating  together,  and 
are  in  fact  always  parallel  to  each 
other. 

A  set  of  four  clocks,  worked  from 
one  piece  of  zinc  2  ft.  square  and 
one  piece  of  coke,  have  been  at 
work  at  Leamington  for  two  years  ; 
and  though  they  were  only  a  trial 
set,  not  over  well  made,  they  have 
never  deviated  from  mean  time  more 
than  a  few  seconds  per  week,  and 
have  never  deviated  from  each  other 
at  all.  The  said  piece  of  zinc  and 
coke  have  been  in  use  during  the 
twenty  years  in  which  Mr  Bright 
has  been  engaged  in  perfecting  his 
invention,  and  on  the  occasion  of  a 
visit  from  a  gentleman  from  Green- 
wich Observatory  for  the  purpose  of 
inspecting  these  clocks,  the  zinc  and 
coke  were  dug  up  and  found  to  be 
apparently  as  serviceable  as  ever. 

An  interesting  fact,  in  connection 
with  this  part  of  the  subject,  is  that 
a  set  of  three  clocks  are  at  work 
with  no  other  battery  than  one  wire 
attached  to  a  gas-pipe  and  the  other 
to  a  piece  of  coke. 

Also  another  pair  of  clocks  are  at 
work  with  one  wire  attached  to  a 
water-pipe  and  the  other  to  a  piece 
of  coke.  A  set  of  five  clocks  may 
be  seen  at  work  at  the  Gun  Cotton 
Office,  173  Fenchurch  Street. 

It  is  thus  evident  that  these  clocks 
require  very  little  power  to  keep  them  in  motion,  and  have 
very  little  friction,  and  it  may  be  expected  that  the  liability  to 


HOROLOGY.  163 


error  will  be  proportionally  diminished ;  and  therefore  much 
may  be  hoped  for  them  in  the  direction  of  good  time-keeping, 
as  well  as  uniformity,  both  great  desiderata  for  railway  and 
commercial  purposes. 

Several  years  ago  Mr  Gammage  invented  a  mercurial  pen- 
dulum with  the  rod  passing  entirely  through  the  mercury. 
This  pendulum  is  used  for  timing  compensation  work,  so  that 
accuracy  is  indispensable.  The  springing  of  a  pendulum  is  a 
matter  that  requires  much  greater  attention  than  it  generally 
receives.  Many  well-made  pendulums  are  badly  sprung,  and 
give  off  unsteady  rates  when  put  to  first-rate  movements.  The 
following  is  the  description  of  the  instrument : — 

A,  steel  rod  passing  through  tube  ;  B,  tube  to  which  lower 
cap  is  attached  ;  C,  glass  jar  to  hold  mercury  \  D,  regulating 
nut,  working  on  screw  cut  on  lower  end  of  rod. 

The  jar  has  a  hole  cut  through  the  bottom  rather  larger  than 
the  tube,  the  outer  edge  is  carefully  ground  into  the  cap,  and 
when  the  pendulum  is  finished  it  is  set  with  cement. 

Mercurial  Pendulum. — Fig.  i  represents  a  pendulum,  with 
a  stirrup  to  support  the  glass  jar.  The  rod  is  steel,  and  about 
4-ioths  wide  by  2-ioths  thick.  The  spring  at  the  top  is  ^ 
in.  wide,  and  2  in.  long.  The  sides  of  the  stirrup  are  steel, 
the  same  size  as  the  rod,  and  are  joined  at  the  top  with  two 
steel  plates.  There  are  also  two  short  pieces  of  the  rod  steel 
put  between  the  plates  and  close  up  to  the  rod,  to  form  a  groove 
for  the  rod  to  slide  in,  the  whole  being  pinned  and  screwed  up 
together  as  shown.  The  bottom  of  the  stirrup  is  a  circular 
plate  of  brass,  hollowed  out  to  fit  the  bottom  of  the  jar,  and 
has  two  forks  to  fit  the  steel  sides,  and  through  which  the 
screws  are  put,  as  shown  at  D.  There  is  also  a  brass  cap 
fitted  to  the  top  of  the  jar,  and  with  forks  to  fit  on  the  steel 
sides  ;  but  it  is  not  screwed  to  them,  so  that  it  can  be  lifted  up 
to  put  more  in,  or  to  take  the  jar  out  of  the  stirrup.  The  glass 
jar  C  is  2  in.  inside,  and  i\  in.  outside  diameter,  and  ']\  or  8 
in.  long.  The  height  of  mercury  has  to  be  about  6J-  in.  \  but 
can  only  be  got  right  by  experiment ;  no  two  pendulums  are 
alike  in  tliis  respect,  as  a  great  deal  depends  on  the  kind  of 
steel  used.-  One  great  advantage  of  the  mercurial  pendulum 
is,  that  it  can  be  very  readily  adjusted.  The  length  of  the 
pendulum  from  the  point  of  suspension  A  to  the  bottom  of  the 


[64 


HOROLOGY. 


FIG.  I 


brass  B  is  about  43  in.  The  bottom  of  the  rod  is  made  into 
a  screw,  and  has  a  large  milled  and  divided  nut  screwed  on 
for  regulating  the  clock.  There  is  also  an  index  screwed  on 
to  the  plate  to  show  how  much  the  nut  is  turned 
round.  The  screw  may  be  20  to  the  inch,  and 
the  nut  divided  into  50,  so  that  if  the  nut  is 
turned  round  one  division,  it  will  raise  or  lower 
the  stirrup  one-thousandth  of  an  inch.  Having 
tried  the  clock  to  see  how  much  it  gains  or  loses, 
the  following  rule  is  given  to  ascertain  how  much 
to  alter  the  nut,  to  bring  the  clock  to  time  at 
once  : — Multiply  the  theoretical  length  of  the 
pendulum  by  2,  and  by  the  number  of  seconds 
gained  or  lost  in  a  day,  and. divide  the  result  by 
the  number  of  seconds  in  a  day  ;  the  quotient 
will  give  the  parts  of  an  inch  by  which  the  pen- 
dulum must  be  lengthened  or  shortened.  The 
theoretical  length  of  a  seconds  pendulum  is 
39-2  in.,  and  the  seconds  in  a  day  86,400". 
Now  suppose  the  gain  of  a  seconds  pendulum 
to  be  three  minutes  per  day,  we  have  39*2  x  2 
=  784  X  180'''=  141 120  -H  86400  =  '163  parts 
of  an  inch,  that  is,  three  turns  and  1 3  divisions 
of  the  nut  by  which  the  pendulum  is  to  be 
lengthened ;  if  the  clock  had  been  losing,  of 
course  the  pendulum  would  require  to  be  short- 
ened. Mr  Denison  says,  in  his  work  on 
"  Clockmaking,"  if  the  screw  is  16  to  the  inch, 
and  the  rod  43  in.  long,  one  turn  of  the  nut  will 
alter  the  clock  one  minute  per  day;  so  that  if  the  nut  is  divided 
into  60,  one  division  will  alter  the  clock  a  second  a  day.  Cold 
weather  is  the  best  for  adjusting  compensated  pendulums,  as 
the  temperature  of  the  clock-room  can  be 
raised  by  fire  or  gas,  and  lowered  by  letting 
the  fire  out.  To  adjust  the  mercury,  let 
there  be  only  6  in.  in  the  jar.  and  regulate 
the  clock  in  the  cold  room,  so  that  it  has  a 
losing  rate  of  say  five  seconds  a  day ;  now  raise 
the  temperature,  and  note  if  the  clock  loses 
still  more,  if  so,  more  mercury  is  required  :  put  in  a  little  :  now 


A 

© 

Jl'L 

0 

r 

J 

i 
■ 

c 

■ 

w 

© 

Fig.  2. 


see  what  the  rate  is,  and  then  lower  the  temperature,  and  see 


HOROLOGY.  165 


if  the  rate  is  the  same.  If  the  rate  is  less  wh"en  the  temperature 
is  lowered,  put  in  some  more  mercury,  and  again  note  the  rate 
and  raise  the  temperature,  and  see  if  the  rate  is  altered,  thus 
repeating  the  process  until  the  rate  is  the  same,  as  near  as  can 
be,  in  heat  and  cold.  The  final  adjustments  had  better  be  left 
perhaps  for  summer  and  winter,  as  long- continued  experiments 
and  observations  are  required  to  obtain  satisfactory  results. 
Adding  to  the  mercury  will  reduce  the  original  rate  five  seconds 
a  day,  so  that  the  clock  will  be  brought  to  time  without  altering 
the  nut  at  the  bottom  of  the  rod  ;  of  course,  if  the  nut  has  to 
be  altered,  the  compensation  will  have  to  be  adjusted  again. 
Unless  the  clock  is  a  good  one,  perfect  in  all  other  respects,  it 
is  not  worth  a  compensated  pendulum. 

Reducing  Hair-Springs. — Hair-springs  may  be  reduced  by 
rubbing  them  down  on  a  flat  oil-stone  with  spirits  of  wine 
instead  of  oil.  Use  the  middle  finger,  giving  a  circular  motion 
to  the  hand  while  rubbing,  and  let  the  pressure  be  even,  but 
not  too  hard,  or  the  spring  may  get  injured.  If  the  watch 
gains  more  than  five  minutes  a  day,  it  will  be  less  trouble  to 
put  in  another  spring.  The  strength  of  the  springs  can  be 
tried  by  weighing  the  balance  with  the  spring,  thus  :  Lay  hold 
of  the  outer  coil  of  the  spring  in  the  tweezers,  and  "  hook"  the 
inner  coil  on  to  the  foot  of  the  verge  or  cylinder,  and  lift  the 
balance  up,  the  spring  will  thus  be  pulled  down  into  a  "  taper 
spiral  ;  "  the  weak  springs  will,  of  course,  have  longer  spirals 
than  the  strong  ones.  Lever  staffs  must  have  a  bit  of  wax  or 
pegwood  stuck  on  to  the  foot  pivot,  and  to  which  the  spring 
can  be  hooked.  The  strength  of  spring  required  depends  on 
the  diameter  and  weight  of  the  balance,  and  the  number  of 
beats  or  vibrations  per  hour,  technically  called  the  "  train." 
The  only  way  to  tell  if  a  spring-  is  the  proper  strength  is  to  put 
it  on  the  watch  and  try  it.  The  springs  are  sold  sized  in  dia- 
meters and  strengths,  and  if  we  could  get  the  balances  sized  in 
diameters  and  weights,  after  a  few  experiments  we  should  be 
able  to  select  the  proper  spring  at  once.  The  results  of  experi- 
ments should  be  entered  in  a  book  for  future  reference  thus :  — 


Train. 

Balance. 

Spring.                    j 

16,200 

Weight. 
10 

Size. 
10 

Strength. 
10 

Size. 
10 

[66  HOROLOGY. 


This  method  is  proposed  for  plain  balances  only  ;  for  superior 
watches,  with  compensated  balances,  the  isochronism  of  the 
hair-spring  has  to  be  ascertained. 

Strength  of  Mainsprings. — The  reason  a  verge  watch 
gains  when  the  strength  of  spring  is  increased  is  that  the 
balance  is  always  connected  with  and  influenced  by  the  main- 
spring or  maintaining  power.  Thus,  when  a  tooth  of  the 
scape-wheel  has  given  impulse  and  escaped  from  one  pallet, 
another  tooth  drops  into  the  other,  and  by  the  "  recoil "  exerts 
the  full  force  of  the  spring  to  shorten  the  vibration,  and  thus 
makes  the  watch  go  faster.  The  horizontal  escapement  is  used 
in  Geneva  watches,  and  to  this  escapement  the  impulse  is  given 
by  the  oblique  faces  of  the  table  acting  on  the  edges  of  the 
cylinder  as  they  pass  out.  The  teeth,  after  giving  impulse, 
drop  on  to  the  outside  and  into  the  inside  of  the  cylinder  alter- 
nately, and  remain  "  dead  "  during  the  vibration.  The  impulse 
is  given  when  the  balance  is  near  the  quiescent  point,  and  the 
balance  is  then  left  to  finish  the  vibration  by  the  combined 
action  of  the  hair-spring  and  its  own  momentum,  without  being 
influenced  by  the  maintaining  power.  If  a  stronger  spring  is 
put  in,  the  impulse  will  be  more  intense,  and  would  cause  the 
balance  to  vibrate  quicker;  but  the  "  friction"  of  the  teeth  on 
the  inside  and  outside  of  the  cylinder  is  also  increased,  and 
thus  counteracts  the  extra  strength  of  the  mainspring.  It  will 
thus  be  seen  that  a  fusee  is  not  required  to  equalise  the  power 
of  the  mainspring,  as  the  watch  will  keep  the  same  time  within 
moderate  limits  whether  the  spring  be  weak  or  strong.  In 
verge  watches,  on  the  contrary,  a  fusee  is  an  absolute  necessity, 
and  the  spring  must  also  be  "  set  up,"  so  that  it  is  as  strong  at 
the  bottom  as  it  is  at  the  top.  For  this  purpose  watchmakers 
use  an  "adjusting  rod,"  which  is  a  steel  rod  with  sliding 
weights  upon  it,  and  a  pair  of  jaws  to  secure  on  to  the  fusee 
square.  The  rod  can  be  bought  at  the  tool-shops  for  about 
IS.  6d.  To  adjust  the  mainspring  the  watch  is  put  together 
without  the  third  wheel,  and  is  held  in  the  left  hand  edgeways 
with  the  fusee  and  barrel  at  the  top.  The  rod  is  secured  to  the 
fusee  square  with  the  weights  at  the  bottom.  The  watch  must 
now  be  wound  up,  and  the  weights  moved  along  the  rod  until 
the  spring  will  just  pull  the  rod  "  over."  The  right  hand  must 
be  kept  in  "  front  "  of  the  rod,  and  thus  ease  it  over,  for  if  it  is 


HOROLOGY. 


167 


let  go  over  too  sudden  it  will  break  the  chain.  Having  set  the 
weights  so  that  their  '•'  leverage "  and  the  strength  of  spring 
when  wound  up  are  counterpoised,  the  watch  is  let  down  and 
the  spring  "  set  up "  until  it  will  pull  the  rod  over  with  the 
same  force  as  it  did  when  wound  up,  or  as  near  as  can  be,  for 
if  the  fusee  is  not  long  enough  and  of  the  right  shape,  it  will 
not  be  possible  to  get  it  exact.  In  marine  chronometers  the 
shape  of  the  fusee  is  altered  until  the  force  is  equal  in  every 
turn,  but  such  extreme  accuracy  is  of  course  unnecessary  in 
pocket  watches.  The  strength  of  spring  required  depends  on 
the  size  of  the  watch,  and  also  whether  it  is  in  perfect  repair  or 
not.  When  the  holes  and  pivots  are  worn,  the  wheels  often 
rub  each  other,  especially  in  thin  movements  ;  and  if  new  holes 
are  put  in,  it  is  seldom  the  wheels  are  so  free  or  the  depths 
(pitchings)  so  good  as  they  might  be,  hence  a  stronger  main- 
spring is  required  to  pull  the  watch  along.  The  strength  of 
the  springs  depends  on  their  breadth  and  thickness  taken 
together,  but  should  be  as  wide  as  the  barrel  will  allow  without 
rubbing  the  cover,  and  must  not  be  too  thick,  or  they  will  not 
make  turns  enough  in  the  barrel.  To  ascertain  the  number 
of  turns  required, 
wind  the  chain  on 
the  barrel  and 
count  the  turns, 
allovvinghalf  aturn 
for  the  spare  end, 
which  is  not  wound 
on  the  fusee.  In 
verge  and  Geneva 

watches  four  effective  turns  are  required ;  and  if  we  allow  half 
a  turn  for  "  setting  up,"  the  spring  must  make  at  least  4|  turns 
in  the  barrel.  To  do  this,  the  spring  should  occupy  one-third 
of  the  barrel,  the  arbor  one-third,  and  one-third  space.  In 
lever  watches  the  barrels  are  smaller,  and  the  spring  should 
make  3|-  turns  in  the  barrel.  Most  lever  watches  have  a  fusee, 
but  do  not  require  adjusting ;  in  fact,  the  fusee  is  too  short  to 
be  correct.  Above  is  a  sketch  of  a  mainspring  punch  made  in 
a  pair  of  common  pliers  thus  :  Drill  a  hole  through  both  jaws 
from  C  to  D  ;  tap  a  screw  into  C  with  the  bottom  end  turned 
down  for  the  punch  ;  chamfer  the  hole  D  with  a  taper- drill  to 
free  the  punchings  ;   fit  a  bridge  over  the  hole  D  between  the 


[68  HOROLOGY. 


jaws,  and  file  away  the  sides,  so  that  when  the  spring  is  put 
through  the  bridge  and  pressed  obhquely  against  the  sides, 
the  punch  will  punch  the  hole  in  the  middle  of  the  spring,  as 
shown  by  the  dotted  lines  at  BA.  This  punch  answers  well, 
and  the  pliers  can  be  used  for  putting  in  pins  as  usual  without 
any  inconvenience.  A  smaller  punch  in  a  pair  of  long-nosed 
follower  pliers  without  the  bridge  is  also  useful.  With  these  a 
hole  can  be  punched  in  the  inner  coil  of  a  spring  for  the  barrel 
arbor  without  uncoiling  the  spring.  The  above  punch  can  be 
also  recommended  on  the  score  of  cheapness,  as  the  pliers  cost 
only  IS.,  and  the  old-fashioned  punch  to  screw  in  the  vice  costs 
IS.  9d.,  and  the  clumsy  Swiss  mainspring  nippers  cost  6s.  6d. 

Geneva  Cylinders. — The  length  of  a  cylinder  can  be 
obtained  by  the  following  method  : — Take  off  both  jewel 
covers,  screw  on  the  cock,  and  take  the  distance  outside  the 
jewel  holes  with  a  pair  of  pinion  gauges — this  is  the  entire 
length,  pivots  and  all.  The  diameter  is  obtained  from  the 
scape-wheel  thus  :  If  the  foot  of  the  cylinder  is  held  between 
two  teeth  and  against  the  point  of  one,  the  heel  of  the  next 
must  be  quite  free  of  the  cylinder.  With  a  depthing  tool,  the 
watchmaker  can  put  the  scape-wheel  and  cylinder  into  it,  and 
see  if  the  cylinder  has  the  same  freedom  inside  and  outside, 
that  is,  the  tooth  should  have  equal  "  drop"  into  the  inside  and 
on  to  the  outside  of  the  cylinder ;  but  the  point  of  the  tooth 
should  not  drop  too  far  into  the  cylinder — just  enough  to  be 
safe  is  all  that  is  required.  There  are  three  dots,  one  on  the 
plate  close  to  the  edge  of  the  balance,  and  another  on  the  rim 
of  the  balance  to  mark  the  place  for  the  hair-spring  stud,  and 
when  the  balance  is  at  rest,  the  dot  on  it  is  close  to  the  middle 
one  on  the  plate.  In  new  watches  these  dots  mark  the  extent 
of  the  balance  and  of  impulse,  that  is,  a  tooth  escapes  when 
the  dot  on  the  balance  reaches  the  outside  dots  on  the  plate. 
Before  the  balance  is  riveted  too  tight  the  cylinder  should  be 
put  in  and  tried,  and  the  balance  turned  round  on  the  cylinder 
until  the  teeth  escape  at  the  dots  ;  you  will  thus  get  the  bank- 
ing, and  also  the  escapement,  right  at  once. 

Silver  Dial  Cleaning, — Take  about  a  teaspoonful  of  salt- 
petre, and  mix  it  with  about  two  dessert-spoonfuls  of  finely- 
powdered  charcoal— willow  coal  is  the  best.  Let  these  be 
ground  together  with  a  little  water  on  a  piece  of  slate,  with  the 


HOROLOGY.  169 


blade  of  a  knife,  then,  by  the  aid  of  a  camel's-hair  pencil, 
spread  a  portion  of  the  mixture  evenly  over  the  surface  of  the 
dial,  which  must  then  be  laid  on  a  piece  of  charcoal,  and  with 
a  blow-pipe,  and  the  clear  flame  of  a  lamp  or  gas  jet,  it  must 
be  made  just  red  hot,  and  kept  so  till  the  wet  powder  has 
ceased  to  fly  about ;  it  must  be  then  thrown  from  the  charcoal, 
hot  as  it  is,  into  a  mixture  of  sulphuric  acid  and  water  (in  the 
proportion  of  about  one  fluid  ounce  of  acid  to  three  half-pints 
of  water) ;  it  will  then  have  a  snow-white  appearance,  and  must 
be  washed  with  a  brush  and  soap  in  clean  soft  water,  and  put 
into  fine  sawdust  till  quite  dry,  or,  what  is  better,  rosewood 
raspings. 

To  Make  a  Clironometer  Oven. — A  box  suitable  for  testing 
watches  with  compensation  balances,  or  even  the  effect  of  high 
temperatures  upon  aneroids,  may  be  very  efficiently  constructed 
as  follows  : — 

Make  an  outer  box,  either  of  mahogany  or  oak,  and  line  it 
with  sheet-iron  or  block  tin ;  let  it  have  an  aperture  in  front  large 
enough  to  admit  of  lighting  the  gas  jets,  which  must  be  placed 
in  the  apparatus  to  obtain  the  required  internal  heat,  the  pipe 
for  which  should  lie  at.  the  bottom  of  the  box  bent  in  the  form 
of  a  circle.  At  about  four  inches  from  the  bottom  a  diaphragm 
of  perforated  sheet-iron  should  be  fitted.  It  need  not  be  made 
a  fixture,  but  should  be  supported  by  brackets  at  the  corners. 
This  diaphragm  will  receive  the  principal  heat  from  the  jets, 
and  tend  to  distribute  it  more  equally.  In  the  interior  space 
a  sheet-iron  trough,  with  overlapping  edges,  should  be  placed 
so  as  to  rest  upon  the  rim  of  the  outer  box.  Its  dimensions 
should  be  such  as  to  allow  a  space  of  two  or  three  inches  in 
clearance  at  the  sides  and  bottom  between  it,  the  outer  box, 
and  the  diaphragm.  Lastly,  a  light  lattice-work  cradle,  made 
of  wood,  should  be  placed  inside  the  inner  iron  box,  for  the 
purpose  of  holding  the  chronometers,  watches,  or  aneroids  to 
be  tested.  The  lid  to  the  whole  apparatus  should  have  a  panel 
of  plate-glass  through  which  the  contents  of  the  cradle  will  be 
visible  always.  The  lid  should  fit  closely  at  the  edges,  so  as 
to  retain  the  heated  air  in  the  cradle.  Apertures  must,  of 
course,  be  provided  at  the  upper  portion  of  the  outer  box  to 
permit  the  products  of  combustion  to  escape.  These  apertures 
should  be  provided  with  sHding  shutters  or  covers,  to  admit  of 


170 


HOROLOGY. 


them  being  entirely  or  partially  opened  so  as  to  regulate  the 
draught,  and  thereby  the  temperature  of  the  interior.  The 
dimensions  of  the  various  parts  are  not  given,  as  the  size  of 
the  box  must  depend  upon  the  various  requirements  of  different 
individuals. 


Gauge  for  Measuring  Watch-Hands. — The  following  en- 
graving and  description  of  a  gauge  for  measuring  watch-hands 
is  forwarded  by  Mr  David  Meek  of  Edinburgh  : — 

The  gauge  stands  upon  three  pillars  \  in.  long,  and  consists 
of  a  disc  of  brass  2^  in.  in  diameter.  In  the  centre  of  this  disc 
is   a  steel-pumping  centre,  while  around  it  are  engraved  21 

circles.  These 
circles  are  to  show 
the  lengths  of  the 
hands,  and  are 
sufficiently  varied 
for  hour  and  mi- 
nute hands  of 
every  kind.  On 
the  outside  of  the 
2 1  St  circle  are 
placed  40  steel 
studs  about  3-16 
of  an  inch  long, 
and  slightly  taper- 
ing, and  of  differ- 
ent sizes.  No.  I 
being  the  smallest, 
and  40  the  largest. 
The  object  of  these 
studs  is  to  gauge 
the  size  of  the  hour-hand  sockets,  and  like  the  circles  for  the 
lengths  are  so  varied  that  they  embrace  every  size  of  socket 
from  the  smallest  Geneva  up  to  the  largest  English  one. 

As  few  watchmakers  would  feel  inclined  to  purchase  a  hand- 
gauge,  owing  to  its  expense,  the  inventor  has,  to  remove  this 
difficulty,  engraved  a  steel-plate  with  circles  on  it,  correspond- 
ing in  size  and  number  to  those  upon  the  real  gauge,  and  with 
small  rings,  corresponding  exactly  in  size  with  the  steel-studs, 
by  which  the  hour  sockets  are  sized.      From  this  plate  cards 


HOROLOGY, 


171 


have  been  printed,  which  serve  nearly  as  well  as  a  real  gauge, 
without  its  expense. 

To  ascertain  the  length  of  a  hand  by  this  gauge-card,  place 
the  socket  or  square  exactly  over  the  small  dot  in  the  centre, 
and  see  which  circle  the  point  reaches  to.  To  obtain  an  hour- 
hand  with  a  particular  size  of  socket,  take  the  size  of  the  hour- 
wheel  socket  with  a  pinion-gauge  or  spring  callipers,  and  then 
see  with  the  callipers  what  ring  corresponds  in  size.  The 
white  space  within  the  rings  denote  the  size  of  hole  in  the 
hour-hand. 

As  there  are  at  least  400  different  sizes  of  hands  in  general 
use  amongst  the  various  kinds  of  watches,  the  watchmaker 
cannot  fail  to  see  the  value  of  a  gauge  which  enables  him  to 
obtain  any  size  of 
hand  he  is  in  want 
of,  or  those  sizes 
most  suitable  for 
his  trade,  besides 
its  other  advan- 
tages, such  as  the 
saving  of  time, 
surplus  stock,  &c. 
Another  ar- 
rangement which 
renders  the  gauge- 
card  still  more  effi- 
cient is  by  placing 
the  watch  -  hands 

on  a  gauge  similar  to  the  second  one.  The  gauge  has  the  size 
of  sockets  as  well  as  length  of  hand  marked  opposite  each.  As 
the  spaces  get  empty,  they  can  again  be  replaced  by  merely 
referring  to  the  numbers  marked  within  the  empty  spaces,  the 
hands  being  fixed  on  the  card  so  as  they  can  be  taken  off  and 
again  replaced  with  little  trouble. 

Watch  Oil,  to  Purify. — Fill  a  phial  three  parts  with  olive 
oil,  and  hang  it  up  in  a  window  for  six  months,  where  it  is 
exposed  to  every  change  in  the  weather.  The  impurities  will 
then  be  precipitated. 

Horizontal  Sun-Dial. —  This  sun-dial  does  not  require  the 
assistance  in  making  it  of  a  dialling  scale — an  instrument  not 


LENGTH     OF 

MINUTE    HA\» 

il7 

— 

^ 

- 

= 

^ 

: 

^ 

-== 

=: 

^ 

LENCTH       0  r 

HQun    HANns 

= 

9 

SIZEi     OF 
sock    E  T5 

0 

D 

5 

5 

0 

0 

0 

0 

0 

0 

0 

28 

172 


HOROLOGY. 


always  to  be  readily  obtained.  On  the  centre  E  describe  a 
circle.  Through  E  draw  the  line  DE,  also  HL,  for  the  12  line, 
at  right  angles  to  DE.     Choose  a  point,  say  L,  on  the  line  HL, 

below  E  ;  through 
L  draw  a  line  par- 
allel to  DE.  Draw 
from  L  a  line  LB, 
making  with  the 
line  LH  an  angle 
equal  to  the  height 
of  the  pole,  or  lati- 
tude of  the  place. 
Set  one  leg  of  your 
compasses  at  E, 
and  take  the  near- 
est distance  to  the 
line  LB,  which  will 
be  found  at  K.  Then  turn  your  compasses,  and  mark  the 
point  H  on  the  line  LH  ;   through  H  draw  a  line  GH  parallel 

to  DE.      From  H, 
^  ^  ^  "^  ^  with    the  distance 

HE,  draw^  the  arc 
HEG.  Divide  this 
arc  into  six  equal 
parts ;  then  from  H 
draw  lines  through 
the  points  of  divi- 
sion in  the  arc  to 
the  li-ne  DE  ;  then 
from  the  point  L 
draw  lines  for  the 
hours>  through  the 
line  DE,  at  the 
points  where  the 
lines  which  divide 
the  arc  meet  the 
line  DE. 

Another  method. 
— Proceed  as  di- 
rected below,  and  you  will  obtain  an  accurate  dial.  Draw  the 
lines  AB  and   CD   at  right  angles  to  each  other,  and  at  the 


NORTH 


HOROLOGY. 


173 


intersection  of  which  as  a  centre,  describe  the  concentric  circles, 
the  size  of  the  dial  required.  The  hne  AB  is  the  six  o'clock  line, 
and  the  line  CD  the  meridian  or  twelve  o'clock  line.  To  fill 
up  the  intermediate  hour  lines,  7,  8,  9,  10,  and  1 1  in  the  quar- 
ter CB  should  be  measured  by  degrees  from  the  meridian  line; 
that  is,  from  1 2  to  11  the  distance  should  be  1 1  degrees  and 
55  minutes  ;  from  12  to  10,  24  degrees  and  26  minutes  ;  from 
12  to  9,  28  degrees  and  13  minutes  ;  from  12  to  8,  53  degrees 
and  44  minutes  ; 
and  from  i2  to  7, 
71  degrees  and  9 
minutes.  The  quar- 
ter AC  must  be  the 
same,  and  the  hours 
4,  5,  7,  and  8,  on 
the  south  side  of 
the  six  o'clock  line, 
should  be  diame- 
trically opposite  the 
same  hours  on  the 
north  side.  The 
gnomon,  as  shown 
in  dotted  lines, 
should  be  an  angle 
of  52  degrees,  and 
raised  directly  over 
the  meridian,  or 
twelve  o'clock  line. 

Inexpensive 
Sun  -  Dial.  —  The 

sketch  shows  the 
upper  part  of  a 
cubical  stone,  hol- 
lowed out  on  three 
sides,  and  set  up 
in  a  slanting  posi- 
tion. The  hollows 
form  half  a  circle. 
The  western  side  cannot  be  shown  in  the  sketch,  but  it  is  the 
same  as  the  east  with  the  figures  reversed.     The  dark  angles 


174 


HOROLOGY. 


of  the  sketch  throw  the  shadow  on  the  hollow  part, 
in  the  usual  manner. 


It  is  set 


Pinion  and  Rack. 

— To  strike  out  a 
pinion  and  rack, 
proceed  as  follows  : 
We  presume  you 
have  your  diame- 
ter of  pitch  -  line 
A.  Divide  it  out 
for  the  teeth  at  A, 
and  strike  them 
out  as  shown  at 
B^  and  C^  The 
B^  in  both  are 
struck  from  a  drop- 
line  D,  as  shown 
by  the  dotted  lines, 
and  C^  are  struck 
from  the  pitch-line 
alone.  There  are 
many  variations,  ac- 
cording to  strength,  the  kind  of  work,  and  different  speeds. 


Diameter  of  Circle. 

— To  get  at  the 
diameter  of  the  pitch- 
circle,  let  AC  and 
DF  be  the  top  and 
bottom  of  the  teeth 
of  a  wheel,  then  B 
and  E  will  represent 
the  pitch-circle.  It 
will  be  clear  that  if 
we  measure  the  dia- 
meter of  C,  the  bottom 
of  the  teeth  on  one 
side,  to  F,  the  top  of 
the  teeth  on  the  other 
side,    it  will    be    the 


same  as  if  we  measure  from  B  to  E. 


GLASS. 


175 


Epicycloidal  Wheel. — A  method  of  converting  circular 
into  alternate  motion,  or  alternate  into  circular,  is  shown  in 
the  accompanying  sketch.  A  is  a  fixed  internal-toothed  annular 
wheel ;  the  pinion  B 
is  attached  upon  a 
crank  arm  CE,  which 
has  its  centre  of  mo- 
tion at  E,  and  carries 
the  centre  C ;  the  rod 
D  being  attached  to 
the  pinion  B  (which 
is  half  the  size  of  the 
annular  wheel)  at  F, 
the  circumference  of 
revolution  of  the  D 
pinion  is  thereby  made 
to  describe  the  right 
line  DG,  coinciding 
with  a  diameter  of 
the  annular  wheel, 
which  is  therefore 
equal  to  the  length 
of  the  stroke  of  the 
engine  to  which  it 
may  be  applied.  This 
arrangement  admits, 
in    small    engines,    of 


a  very 


elegant    application   known   as 


White's  parallel  motion. 


Glass,  to  Cut  without  a  Diamond. — This  operation  unites 
utility  with  amusement.  Take  a  bit  of  walnut-tree,  cut  one 
end  to  a  point,  put  that  end  into  the  fire  till  it  is  red  hot ;  while 
the  stick  is  burning,  draw  on  the  glass  with  ink  the  form  you 
mean  to  cut ;  then  take  a  file,  or  a  bit  of  glass,  and  scratch 
the  place  you  intend  to  begin  your  section  ;  then  take  the  wood 
red  hot  from  the  fire,  and  lay  the  point  of  it  about  the  i-20th 
part  of  an  inch  from  the  marked  place,  taking  care  to  blow 
always  on  that  point,  in  order  to  keep  it  red  ;  tallow  the  draw- 
ing traced  on  the  glass,  leaving  the  same  interval  as  before. 
The  pieces,  with  slight  pressure,  will  then  divide. 

Another  method. — Take  any  vessel  you  want  cut,  and,  having 


176 


GLASS. 


heated  a  poker  in  the  fire  till  it  is  almost  red  hot,  but  not  quite, 
apply  it  to  the  part  you  wish  the  crack  to  begin.  Having  held 
it  to  the  part  for  about  a  minute,  remove  the  poker,  and  wet 
the  place ;  the  glass  will  immediately  crack.  Having  now 
begun  the  crack,  you  may  lead  it  in  any  direction  by  merely 
drawing  the  hot  'poker  in  the  direction  you  want.  This  is  ex- 
tremely useful  in  many  chemical  experiments,  where  you  are  in 
want  of  proper  apparatus.     Glass  tubes  may  be  cut  with  a  file. 

To  Cut  Circular  Pieces  of  Glass. — If  the  amateur  has  a 
turn-table  on  which  he  mounts  his  objects,  and  a  writing 
diamond,  he  has  all  that  is  required  to  cut  the  circular  pieces 
of  glass.      It  is  only  necessary  to  fix  the  square  pieces  of  glass 

on  the  centre  of  the 
table,  and  hold  the 
diamond  with  the 
right  hand  while  he 
turns  the  table  with 
the  left. 

The  following 
diagram  will  illus- 
trate all  that  is  re- 
quired : — -A  is  the 
stand  for  table ;  T, 
table;  P,  pole  fixed 
into  stand  of  table; 
C,  arm  to  hold  the 
diamond;  K,K, K, 
keys  to  tighten  the 
aim  C  and  the  dia- 
mond D  j  G,  the 
square  piece  of  glass  fixed  to  table  by  the  two  pieces  of  iDrass 
B,  B,  which  each  have  two  holes,  so  as  to  tighten  the  piece  of 
glass  G.  The  pieces  of  brass  are  fixed  by  two  screws,  as  can 
be  seen.  These  two  pieces  of  brass  will  do  to  hold  the  slide 
on  the  table  when  required  for  mounting  objects. 

To  Cut  a  Circular  Hole  in  a  Sheet  of  Glass. — Drill  a 
number  of  small  holes  close  together  to  form  a  circle  as  large 
as  the  hole  is  required  to  be,  then  join  the  holes  with  a  small 
file.  The  drill  must  be  quite  hard,  and  both  drill  and  file 
wetted  with  spirits  of  turpentine  and  oil  of  lavender. 


1                 1 

,-^.      i?2-^ 

r 

IT                             .  ■                    J| 

y  ■ 

A 

ff^^ 

GLASS.  177 


Designs  on  Glass. — A  mode  of  effecting  this,  which  is  a 
modification  of  the  process  by  which  copperplate  engravings 
on  paper  are  transferred  to  porcelain,  has  been  invented  in 
France.  As  fine-lined  copperplate  engravings  would  not  adhere 
to  glass,  others  having  considerable  depths  are  used ;  also,  to 
impart  to  the  enamels  that  thickness  which  the  glass  requires, 
stearates  and  oleates  are  added  to  the  silicates  and  borosilicates, 
which  serve  to  support  or  to  fuse  the  coloured  and  colouring 
oxides  ;  and,  for  a  vehicle,  a  solution  of  resin  in  ether  or  ben- 
zine is  added  to  the  mixture.  Impressions,  taken  mechanically 
on  paper  with  this  ink  from  engraved  rollers,  are  transferred 
to  the  glass,  which  is  then  treated  as  in  similar  processes  with 
porcelain,  and  is  finally  placed  in  the  furnace.  Effects  of  great 
artistic  merit  are  thus  obtained  at  a  trifling  cost. 

To  Transfer  Engravings  on  Glass. — Metallic  colours  pre- 
pared and  mixed  with  fat  oil  are  applied  to  the  stamp  on  the 
engraved  brass  or  copper.  Wipe  with  the  hand  in  the  manner 
of  the  printers  of  coloured  plates  ;  take  a  proof  on  a  sheet  of 
silver  paper,  which  is  immediately  transferred  on  the  tablet  of 
the  glass  destined  to  be  painted,  being  careful  to  turn  the 
coloured  side  against  the  glass.  It  adheres  to  it,  and  so  soon 
as  the  copy  is  quite  dry,  take  off  the  superfluous  paper  by 
washing  it  with  a  sponge ;  there  will  remain  only  the  colour 
transferred  to  the  glass,  which  will  remain  fixed  by  passing  the 
glass  through  the  ovens.  The  basis  of  all  the  colour  employed 
in  painting  on  glass  are  oxidated  metallic  substances.  In 
painting  on  glass  it  is  necessary  that  the  matter  should  be  very 
transparent. 

To  Draw  on  Glass. — Grind  lampblack  with  gum- water, 
and  some  common  salt.  Draw  the  design  with  a  pen  or  hair- 
pencil. 

To  Paint  Glass  Gold  Colour. — Take  silver  i  oz.,  antimony 
J  oz.  Mix  them  in  a  crucible,  then  pound  the  mass  to  powder, 
and  grind  it  on  a  copper  plate  \  add  to  it  yellow  ochre  or 
brickdust,  calcined  again,  1 5  oz.,  and  grind  them  well  together 
with  water. 

To  Paint  Glass  Red. — Take  jet  4  oz,,  litharge  of  silver 
2  oz.,  red  chalk  i  oz.,  powder  them  fine,  and  mix  them, 

M 


178  GLASS. 


Materials  for  Opaque  Enamels. — Calcine  30  parts  of 
lead  with  3  3  of  tin,  with  the  usual  precautions  ;  then  take  of 
this  calcined  mixed  oxide  50  lbs,,  and  as  much  of  powdered 
flints  (prepared  by  being  thrown  into  water  when  red  hot,  and 
then  ground  to  powder),  and  8  oz.  of  salt  of  tartar ;  melt 
the  mixture  in  a  strong  fire  kept  up  for  ten  hours,  after  which 
reduce  the  mass  to  powder. 

Micagraphy. — This  is  the  name  given  to  a  new  process  of 
producing  ornamental  effects  on  sheets  of  mica.     The  use  made 
of  this  new  process  has  been  as  yet  confined  to  the  ornamen- 
tation of  lamps  and  shop-windows,  but  it  may  be  used  as  a 
cheap  substitute  for  stained  glass.      The  sheets  of  mica  can  be 
painted  in  any  required  manner,  and  the  work  preserved,  it  is 
said,  by  means  of  a  varnish,  or  the  painting  may  be  fixed  like 
enamel  on  the  mica  by  the  use  of  different  pigments  and  the 
aid  of  3.  furnace,  the  pieces  of  painted  mica  being  afterwards 
fixed,  with  the  coloured  side  within,  on  the  glass  of  the  windows. 
This  is  the  mod^  of  proceeding  : — After  the  mica  is  split  into 
laminpe  and  trimmed  into  shape,  it  is  glued  down  upon  card- 
board ta  be  polished  anji  printed.     The  former  operation  is 
performed  by  means  of  a  soft  rubber  moistened  with  a  solution 
of  soap  or  sulphuric  acid  extremely  diluted  with  gum-water  : 
the  printing  is  performed  in  the  ordinary  manner  or  by  transfer, 
in  order  to  present  the  design  in  the  natural  position  so  as  to 
iDe  seen  by  transparency.      Opaqueness  is  produced  by  a  pre- 
vious coat  of  varnish  or  a  metallic  ground  obtained  by  means 
of  leaf  or  powder.     The  colours  are  laid  on  as  in  illuminated 
works,  and  the  ordinary  pigments  may  be  employed,  and  after- 
wards covered  with  a  transparent  spirit  varnish,  or,  as  before 
stated,    enamel  colours   may  be  used  and  the  sheets  passed 
through  the  fire.      It  is  admitted,  however,  that  in  the  latter 
case  one  great  advantage  of  the  process,  namely,  cheapness,  is 
in   a  great   measure  sacrificed.      When  the  ornamentation^ is 
completed,  the  mica  is  removed  from  the  card  and  fixed  on 
glass,  or  any  other  substance,  by  means  of  a  solution  of  gum 
sandarac  and  mastic  in  potash  and  alcohol.      It  is  said  that, 
with  ordinary  care,  the  junction  of  the  pieces  of  mica  in  a 
mosaic  or  other  work  is  quite  imperceptible,  so  that,  in  the  case 
of  a  painted  window,  there  is  no  other  limit  but  the  size  of  the 
glass  on  which  the  mica  is  fixed. 


WOOD-  WORKING. 


179 


Soluble  Glass. — A  covering  for  decayed  wood  and  other 
practical  purposes.  Fifteen  parts  of  powdered  quartz,  10  of 
potash,  and  i  of  charcoal.  These  are  melted  together,  worked 
in  cold  water,  and  then  boiled  with  5  parts  of  water,  in  which 
they  entirely  dissolve.  It  is  then  applied  to  wood-work,  or  any 
other  required  substances.  As  it  cools  it  gelatinizes,  and  dries 
up  into  a  transparent  colourless  glass  on  any  surface  to  which 
it  has  been  applied.      It  renders  wood  nearly  incombustible. 

Woods,  Strength  of. — The  strength  of  different  woods  to 
resist  a  compressive  strain  depends  upon  the  value  of  the 
absolute  force  or  weight  which  has  been  found  by  experiment 
to  crush  them,  and  which  has  a  very  wide  range.  The  annexed 
table  shows  the  crushing  weight  for  all  the  woods  which  are 
used  in  the  various  branches  of  constructive  art,  and  from 
these  numbers  and  simple  rules  it  will  be  easy  to  calculate  the 
strength  of  pillars  of  different  lengths  and  sizes. 


Description  of  Timber- 


Crushing 

Weight  in 

cwts.   per 

square  inch. 


Alder 

Ash 

Birch  

Beach 

Box 

Elm 

Ebony 

Hornbeam, 

Larch 

Mahogany , 
Oak 

Pine  (Red) 

Pine 

Sycamore . 

Spruce 

Teak 

Watergum 


61-50 

80 
104 

83 

92 

92 

170 

65 
50 

73 
89-25 

53-50 
68-75 

5175 
48 

63-25 
61 

108 
90 


Safe  Load 

in  cwts. 

per  square 

inch. 


15-40 

20 

26 

21 

23 

23 

42-25 

16-25 

12  50 

18-25 

22.25 

13-40 

17-20 

13 
12 

15-80 

15-25 

27 

22-50 


Timber,  where 
Grown. 


England, 
America. 


West  Indies. 

America. 

England. 

Honduras. 

England. 

Canada. 

Dantzig. 

America. 

The  Baltic. 

England, 

America, 

Africa. 

East  Indies. 


Warped  Wood. — The  best  method  of  straightening  warped 
wood  is  to  wet  it  well  on  the  hollow  side,  and  clamp  a  piece  of 
hot  wood  top  and  bottom  with  hand-screws,  such  as  cabinet- 


i8o 


WOOD-  WORKING. 


makers  use,  until  cold  ;  then,  if  convenient,  screw  a  piece  of 
hard  wood  on  the  under  side,  and  let  it  remain  on.  Another 
plan  is  to  cut  down  the  middle,  shoot  the  edges,  glue  together 
again,  and  plane  flat. 


Dovetailing. — In  plate  i  several  ways  of  working  are 
shown,  but  as  much  depends  upon  the  parts  being  properly- 
proportioned  which  are  to  fit  into  each  other,  so  that  the  pin 
or  socket,  partly  represented  in  fig.  i,  called  the  pin  of  the 
dovetail,  and  that  in  fig.  2,  called  the  socket,  shall  be  as  nearly 
as  possible  of  equal  strength,  we  lay  down  some  rules  for  the 
guidance  of  the  workman,  and  here  refer  to  the  pin  only  in  fig. 
I,  for  the  socket  is  made  to  correspond  to  it.  Let  ABCD  be 
a  scanthng  required  to  be  joined  to  another  by  means  of  a 
single  dovetail.  Now  as  much  will  depend  on  the  form  of  the 
dovetail  as  the  proportion  it  bears  to  the  parts  cut  away,  we 
will  endeavour  to  lay  down  the  principle  on  which  the  greatest 
strength  is  maintained.  Having  squared  the  ends  of  the 
scanthng,  and  gauged  it  to  the  required  thickness  AIKLM, 

divide  IM  into  three 
equal  parts  at  KL. 
Let  KL  be  the  small 
end  of  the  dovetail, 
and  make  the  angles 
IKG  and  MLH 
equal  about  75  or 
80  degrees.  Now 
make  GE  and  FH 
parallel  to  AN  and  BO.  Here  introduce  the  saw,  and  cut 
away  the  pieces  AIKGEN,  and  BMLH  FO  ;  and  having  cut 
fig.  2  to  correspond  by  making  the  form  of  the  dovetail  on  the 
top  of  the  piece  ABCD,  it  will  fit  together,  as  shown  in  fig.  3. 

According  to  the  texture  of  the  wood,  we  may  make  the 
bevel  of  the  dovetail  or  angle  IKG,  fig.  i,  either  more  or  less. 
Hard,  close-grained  wood,  not  apt  to  rive  or  split,  will  admit  of 
a  greater  bevel  than  that  which  is  soft  or  subject  to  chip:  thus 
the  dovetail  in  deal  must  be  beveled  less  than  that  in  hard 
oak.  It  is  a  fault  in  many  workmen  that  they  give  the  dove- 
tails too  much  bevel,  which,  instead  of  holding  the  joint  firmly 
together,  weakens  it.  This  may  be  observed  if  we  compare 
the  dovetailing  of  the  cabinetmaker  and  the  joiner ;  the  former 


^ 

^ 

>^ 

\2_ 

->— 

B 

^       .^—^\\ 

>- 

)i 

WOOD-  WORKING. 


[8i 


has  very  little  bevel,  while  the  latter  has  very  much.  Even 
with  respect  to  the  appearance  of  the  work,  the  one  looks  neat, 
and  is  at  the  same  time  strong  ;  while  the  other,  appearing  to 
aim  at  great  strength,  looks  clumsy,  and  is  in  reality  the 
weaker.  Fig.  4  represents  the  dovetail  in  common  use  for 
drawer  fronts,  &c.,  when  it  is  wished  to  hide  the  appearance  of 
the  joint  in  front.  The  board  ABCD  is  cut  with  the  pin,  and 
AEFB  with  the  socket;  the  pins  in  this  sort  of  dovetail  are  in 
general  placed  one 

c       -  -       -  D 


Y-lT-lTT^    fi/i=Hd1 


inch  apart.  Fig.  5 
represents  the  pin 
part  of  tap  dove- 
tail, which  when 
put  together  shows 
only  a  joint,  as  if 
the  pieces  were 
riveted  together,  as  shown  in  fig.  6  ;  the  part  ABCD  repre- 
sents the  pin,  and  the  part  EFGH  the  socket  dovetail,  and 
when  put  together  only  shows  the  line  HG  as  a  joint ;  and  if 
the  corner  AB  is  rounded  to  the  joint  GHT,  it  will  appear  as 
if  only  mitred  together.  This  kind  of  dovetail  is  very  useful 
for  many  purposes  where  neatness  is  required.  Fig.  7  is  a  still 
neater  dovetail.  Instead  of  the  square  shoulder  or  rebate  in 
AB,  it  is  cut  into 
a  mitre,  and  the 
other  piece  is  made 
to  correspond.  An- 
other very  neat  way 
is  shown  in  fig.  8, 
where  the  joints  are 
first  formed  into  a 
simple  mitre,  and 
then  keyed  together 
either  by  making  a 

saw  kerf  in  a  slanting  direction,  as  shown  at  AB,  or  by  cutting 
out  a  piece  as  at  CD  in  the  form  of  a  dovetail,  and  fitting  a 
shp  in  of  the  required  form.  The  first  method,  as  AB,  is 
amongst  workmen  called  keying  together ;  the  second,  as  CD, 
is  key  dovetailing ;  the  last  method  is  shown  at  fig.  9,  and  may 
be  termed  mitre  dovetail  grooving,  the  part  AB  being  formed 
with  shoulders  cut  to  the  required  bevel,  and  a  piece  left  for 


y'EL 

H^ 

i      - 

_! 

A 
0 

8 

^ 

A/ 

\B 

-P 

^ 

^ 


[82 


WOOD-  WORKING. 


the  pin  dovetail,  which  is  inserted  into  the  socket  dovetail, 
made  to  correspond  to  it  in  the  piece  CD,   which  has  been 

previously     formed 
fi&  I  ^       into  a  mitre.     This 

method,  though  not 
much  employed, 
may  be  used  with 
great  advantage  in 
many  cases,  parti- 
cularly when  we 
wish  to  join  any 
pieces  together  the 
lengthway  of  the 
grain. 

Annexed  are  three 
other     illustrations 
of  dovetailing,  suf- 
ficiently   shown    in    the    engravings    as    to    need    no    further 
description. 


Wood  Staining. — To  Stain  Wood  a  Mahogany  Colour 
before  Polishmg. — Make  a  strong  or  weak  solution  of  logwood, 
according   to   shade    required,  to   which  add  a  few  drops  of 

hydrochloric  acid  ; 
then  stain  the  ar- 
ticle. When  dry, 
give  a  coat  of  lin- 
seed oil,  and  it  is 
ready  for  polishing. 
If  boiled  or  strong 
drying  oil  is  used,  a 
much  darker  shade 
is  obtained ;  with 
the  latter  it  becomes 
almost  black. 

Another  method. 
—  Boil      logwood 
chips  in  water,  add- 
ing a  little  soda  or  potash  to  bring  out  the  colour.    Apply  with 
a  brush,  and  use  French  polish  when  dry. 

Rosewood  Stain. — A  stronger  decoction  of  logwood  must  be 


WOOD-  WORKING. 


t83 


used,  and  the  process  must  be  repeated  several  times.     To 

produce  the  fibres,  put  some  iron-filings  or  turnings  in  strong 

vinegar ;  let  it  stand  for  some  years,  and  then  brush  the  wood 

over  with  the  solu- 
tion.      When    dry, 

polish    with    bees- 
wax and  turpentine. 
Another  method. 

— Dissolve    half   a 

pound  of  potash  in 

2  gallons  of  water, 

and  add  to  it  half  a 

pound  of  red  san- 

der-wood.      When 

all    the    colour    is 

extracted  from  the 

wood, add  5  pounds 

of  gum  shellac,  and 

dissolve    it   over   a 

quick  fire.     This  stain  should  be  used  on  a  ground  previously 

with  logwood  stain. 

Another  method. — If  with  a  brush  dipped  in  the  brightening 

liquid  you  draw  veins  on  wood  prepared  with  the  black  stain, 

a  very  good  effect  is  produced. 

Red  Stain  for  Bedsteads  and  Common  Chairs. — Lay  on  one 

or  two  coats  of  common  archil,  and  when  dry  brush  over  with 

a  hot  solution  of  pearl-ash  in  water. 

To  improve  the  Colour  of  Stai^is, — With  -1  oz.  of  nitrid  acid 

diluted  with  4  oz.  of  water,  mix  a  teaspoonful  of  muriatic  acid 
and  I"  oz.  of  grain  tin.  Keep  in  a  bottle  well  corked,  and  use 
after  it  has  stood  two  days. 

To  Stain  Beech  a  Mahogany  Colour.-^ln  a  pint  of  rectified 
spirits  of  wine  put  an  ounce  of  dragon's  blood.  Shake  the 
bottle  which  contains  it  frequently  until  the  dragon's  blood  is 
dissolved.     When  this  is  the  case,  the  stain  is  ready  for  use. 

Black  Stain  for  imjnediate  use. — Take  i  lb.  of  logwood 
chips  and  boil  in  4  quarts  of  water,  and  lay  it  on  the  work 
while  hot.  Make  a  similar  decoction  of  logwood  to  the  last, 
and  add  to  it  i  oz.  copperas  and  2  oz.  verdigris  ;  strain  and 
put  into  it  I  lb.  of  rusty  steel  filings,  and  with  this  go  over  the 
work  a  second  time. 


1 84  HOUSE  AND  GARDEN. 

Protection  of  "Wood  Carvings. — Worm-eaten  wood  may- 
be saved  from  further  ravages  by  fumigating  it  with  benzine, 
whereby  the  worm  is  destroyed.  Another  way  is  to  saturate 
the  wood  with  a  strong  solution  of  corrosive  sublimate — a  pro- 
cess which  may  be  advantageously  employed  to  protect  carvings 
in  wood.  But  as  sublimate  destroys  its  colour,  it  will  be 
necessary  to  restore  the  latter  by  ammonia,  and  then  by  a  very 
dilute  solution  of  hydrochloric  acid.  The  holes  made  by  the 
worm  may  then  be  injected  with  gum  and  gelatine,  and  a  var- 
nish of  resin  dissolved  in  spirits  of  wine  should  afterwards  be 
applied  to  the  surface. 

Shooting  Boards  for  Joiners. — This  plan  brings  the  two 
edges  of  boards  true  for  glueing  together,  and  possesses  evident 
advantages  over  those  in  general  use.  a^  bed  of  some  hard 
wood ;  bb^  table  supported  by  blocks  ccc ;  d,  a  block  carefully 

planed    and   fitted 

K  B    ra       ^^  ^^^^^  angles  to 

n^,    •  ...  't^'^    ^^^    ^^^^^'       ^^^^ 

'  a,  this  board  the  whole 

of  the  plane-iron 
is  brought  into  use,  instead  of  one  part  only,  as  in  the  board 
usually  adopted.  Of  course  the  plane-iron  would  have  to  be 
perfectly  straight  on  its  edge,  otherwise  it  would  bring  the 
edges  of  the  board  false. 

Waterproof  Mortar. — The  admixture  of  coal-dust  with 
mortar  renders  it  impervious  to  water.  This  waterproof  mortar 
may  be  made  by  mixing  two  parts  of  fine  cement  with  one  part 
coal-dust  reduced  to  a  very  fine  powder,  and  one  and  a  half 
parts  slacked  lime ;  then  adding  water,  so  as  to  produce  the 
desired  consistence.  Mortar  thus  made  possesses  great  soli- 
dity ;  but  the  darkness  of  its  colour  is  often  an  obstacle  to  its 
use. 

Damp  on  "Walls. — A  complete  cure  from  damp  exuding 
from  a  brick  wall  upon  which  no  plaster,  much  less  paper, 
would  adhere,  on  account  of  its  having  been  several  times 
saturated  with  sea-water,  has  been  effected  by  using  "  Italian 
plaster."  The  cost  is  but  little  more  than  that  of  Portland 
cement,  and  may  be  papered  upon  forty-eight  hours  after  being 
used,  without  any  risk  of  damp  or  discolouration. 


i 


HOUSE  AND  GARDEN. 


i8s 


Cleaning  Paint. — Dissolve  2  oz.  of  soda  in  a  quart  of  hot 
water,  which  will  make  a  ready  and  useful  solution  for  cleaning 
old  painted  work  preparatory  to  repainting.  The  mixture  in 
the  above  proportions  should  be  used  when  warm,  and  the 
wood-work  be  af- 
terwards washed  M„^  ^ 

with  water  to  re-  ^ ' 

move  the  remains 
of  the  soda. 


Door -Spring. 

— The  following 
is  suggested  as 
a  simple  spring 
for  a  door.  It 
consists  of  half  of 
a  hook-and-eye 
hinge,  fixed  in 
two  places  on  the 
door-stile,  and  in 
one  place,  near 
the  top,  on  the 
facing  or  archi- 
trave. A  piece 
of  wire,  |-  of  an 
inch  in  diameter, 
passes  from  the 
lower  eye  straight 
through  the  cen- 
tral one,  and  is 
then  bent  out,  so 
as  to  pass  into 
the  upper  eye  on 
the  architrave. 
The     action     of 

opening  the  door  strains  the  wire,  and  the  spring  acts  by  its 
reverting  to  its  former  position. 


Marble,  Imitating. — How  to  make  a  stucco  mantelpiece 
look  like  black  marble.  Make  a  mould  of  wood  and  line  it  with 
plate-glass ;  and  mix  stucco  with  size,  to  keep  it  from  setting 


1 86  HOUSE  AND  GARDEN. 

too  fast.  The  colour  ought  to  be  put  in  among  the'  stucco 
before  mixing;  then  spread  a  thin  coat  on  the  glass,  rub  it 
well  to  take  out  the  air-bubbles,  and  fill  the  mould  up  with 
clean  stucco  before  the  first  sets.  After  it  has  set,  dip  the 
mould  in  water,  and  it  will  come  out  easy.  So  soon  as  it  is 
dry,  dip  it  into  size  mixed  with  black,  and  then  cover  with 
black  varnish.  Do  not  touch  it  with  the  fingers  after  it  has 
come  out  of  the  mould.  Use  mineral  colours,  and  be  certain 
that  there  is  no  oil  in  them.  Any  other  kind  of  marble  may, 
by  a  little  ingenuity,  be  imitated  when  the  first  coat  is  laid  on. 
A  better  kind  of  mould  can  be  made  by  taking  an  original  and 
covering  it  with  clean  glass,  and  then  pouring  wax,  such  as 
plasterers  use,  over  the  glass. 

Architectural  Ornaments  in  Relief. — For  making  archi- 
tectural ornaments  in  relief,  a  moulding  composition  is  formed 
of  chalk,  glue,  and  paper  paste.  Even  statues  have  been  made 
with  it,  the  paper  aiding  the  cohesion  of  the  mass. 

To  Take  out  Iron  Stains. — Mix  in  a  bottle  equal  quantities 
of  fresh  spirit  of  vitriol  and  lemon  juice,  wet  the  spots,  and  in 
a  few  minutes  rub  them  off  with  a  piece  of  soft  linen. 

Anti-Pestilential  Vinegar. — Take  acetic  acid  (5°)  900 
grammes,  camphor  in  powder  5  grammes,  crystallised  phenic 
acid  100  grammes.  This  combination  of  three  antiputrescents 
is  said  to  be  extremely  useful,  and  for  hygienic  purposes  far 
superior  to  "  vinegar  of  the  four  thieves,"  as  toilet  vinegar  was 
once  called.  It  has  been  used  on  board  ship  to  keep  cabins 
sweet. 

Preparation  of  Walls  in  Tempera.— When  it  is  wished 
to  colour  a  wall,  not  retaining  the  plaster  or  stone  as  a  ground, 
the  following  order  must  be  observed.  First  mend  any  broken 
parts  with  a  mixture  of  putty  and  plaster-of-Paris  neatly  put 
on  with  a  spatula  or  palette  knife,  and  smoothed  down  ;  then 
brush  over  the  walls  with  a  size,  composed  of  i  lb.  of  good 
glue  dissolved  in  i  gallon  of  hot  water,  thickened  with  some 
red  lead,  or  else  with  Young's  patent  size.  Give  this  sufficient 
time  to  dry.  Now  proceed  to  make  your  ground  colour,  which 
we  will  suppose  to  be  what  is  usually  called  vellum  tint,  as 
follows  :  —  In   a   large  double-sized   paint-pot   put   3   lbs.  of 


HOUSE  AND  GARDEN. 


187 


gilder's  whiting,  cover  it  with  water,  and  let  it  be  until  it  be 

perfectly  broken  up  and  saturated,  and  the  effervescence  has 

subsided.      Then  pour  off  the  water,  and  stir  with  a  thick  stick 

until  the  mass  has  attained  the  consistency  of  dough.      Melt 

Young's  patent  size  not  diluted,  and  pour  upon  the  whiting, 

stirring  well  up,  and  then  straining  while  warm  to  free  from 

impurities.      Let  this  stand  several 

days  in  a  cool  place  until  it  is  formed 

into  a  weak  trembling  jelly,  so  as  to 

be  worked   with   ease  with    a    stiff 

brush.     Before  the  size  is  added  it 

may  be  stained  to  any  tint  which  is 

desired  by  the  addition  of  the  pro- 
per   colour    ground    in    water.       It 

should  be  observed  that  all  colours 

in  distemper  dry  lighter  than  when 

first  applied,  so  that  the  only  way  to 

secure  the  requisite  tint  is  to  make 

experiments  upon  a  piece  of  paper  or 

card  until  the  proper  tint  is  reached. 

The    colour    must  then  be  applied 

to  the  walls  in  its  cold  and  jellied 

state.     For  this  purpose,  use  a  large 

hog's-hair  brush,  and  work  with 
decision  and  freedom,  taking  care 
not  to  retouch  any  portion  of  the 
work,  but  to  cover  the  ground  well 
as  you  proceed.  The  wall  should 
be  divided  by  your  eye  into  squares, 
advancing  from  one  to  another  in 
regular  succession,  and,  of  course, 
beginning  from  above.  Unless  for 
some  special  purpose,  your  ground 
should  never  be  pure  white,  but  be  stained,  however  little,  with 
black,  blue,  ochre,  or  chrome  yellow,  to  take  off  the  raw  appear- 
ance ;  where  a  coloured  ground  is  needed,  proceed  in  the  same 
way  as  above  described,  commencing  with  a  larger  or  smaller 
quantity  of  whiting,  and  tempering  it  in  the  colour  to  the  degree 
required. 


Chimney  Cowls. — The  above  simple  arrangement  of  cowls, 


1 88 


HOUSE  AND  GARDEN. 


constructed  on  the  principle  of  the  air  blowing  through,  draws 
up  the  smoke.  They  have  been  largely  tried,  and  have  per- 
fectly succeeded. 


Cowl  for  Smoky  Chimneys.  —  Let  O  be  a  tube  of  any 
length,  9  in.  diameter ;  S  also  is  a  tube,  and  base  to  O,  being 
14  X  9  in.  ;   N  is  a  tube   16  x   loj  in.,  upon  which  is  fixed 


another  tube  M,  at  XE 


the  wind, 
at  BD. 


having    to    pass  through  it, 


M  is  a  tube  through  which  air  passes 
to  carry  off  the 
smoke.  In  M  ab  is 
20  in.,  ^^is  17  in., ac 
is  I  o  in.  diameter,  c:i: 
is  3  in.,  £d  is  4  in. 
Visa  funnel-shaped 
piece  of  iron,  which 
is  fixed  at  AC,  being 
from  the  line  AC  to 
the  opening  K,  4J 
in.,of  which  K,  being 
a  tube,  is  2  in.  long 
by  I J  in.  diameter, 
which  passes  over 
the  mouth  of  N,  i| 
in.;  BD  is  the  out- 
let ;  O  is  a  rod  of 
iron  fixed  at  the  top 
of  O,  upon  which 
turns  M  at  the  point 
T.  Z  is  a  piece 
of  sheet-iron  fixed 
on    M,   from   T   to 


against    the    wind, 
bringing  the  cone  V 
open  to  it,  by  which 
carries  off  the  smoke 


Stains  on  Marble,  to  Remove. — Various  plans  are  adopted 
for  taking  iron  and  ink  stains  from  marble — such  as  chimney- 
pieces  and  wash-hand  stands,  &c.,  but  the  following  will  be 


HOUSE  AND  GARDEN. 


found  most  practical  : — Mix  unslacked  lime  in  very  fine  powder 
with  strong  soap  ley ;  make  it  thick,  and  leave  on  the  marble 
for  more  than  a  week.  Then  wash  off  with  a  thick  lather 
of  soft  soap,  boiled  in  soft  water.  Clear  off  the  soap,  and 
brush  with  a  little  hme  powder,  and  a  fine  pohsh  will  be  the 
result. 


Closet  Construction. — Dry  earth  is  no  doubt  a  great  deo- 
doriser, and  the  principle  has  been  adopted  with  considerable 
success.  It  answers  under  two  conditions,  that  the  earth 
should  be  thrown  down  perfectly  dry,  and  kept  dry ;  but 
is  it  so .?  How  many  receptacles  are  commonly  emptied 
into  the  waste,  or,  if  not^  down  some  open  sink .?  We 
may  suppose  that  in  a  town  there  will  be  a  greater  adapta- 
bility of  water  than  in  the  country,  whilst  in  the  latter  there 
will   probably  be  attached  to  the  dwelling  a  strip  of  garden 


ground  into  which  the  manure  may  be  deposited,  as  in  the 
earth  closets.  The  annexed  sketch  will  illustrate  the  prin- 
ciple : — ^,  closet  pan  \  b,  wall  of  house ;  c,  a  wooden  water- 
spout for  carrying  down  any  spare  water  from  the  roof,  or  for 
letting  gases  pass  away  into  the  open  air ;  c,  water-tight  tank 
with  flag  top,  calculated  to  require  emptying  of  sohd  contents 
once  in  three  years ;  ^,  an  1 8-in.  drain,  running  into  a  second 
tank  e,  which  holds  the  liquid  manure  at  the  bottom  of  the 
garden ;  _/J  a  smaller  waste-pipe  of  some  length  connected  with 
a  drain.  The  pan  is  a  simply- made  affair  of  sheet  zinc 
painted,  with  a  rim  turned  over  at  the  top,  and  a  bottom  on 
hinge  to  balance  about  a  quart  of  water  or  so.  Over  the  rim 
comes  a  false  seat,  and  all  is  air-tight.     The  rim  is  embedded 


190 


HOUSE  AND  GARDEN. 


in  putty.      After  use  a  small  quantity  of  water  is  poured  down 
with  a  can ;    but    where  water  from  the  main  can  be    pro- 


is  not  the  slightest  unpleasantness. 


cured,  there  would 
be  no  difficulty  in 
adjusting  a  com- 
mon pipe  to  the 
side  of  the  basin, 
with  an  ordinary 
tap  inserted  in  the 
length  of  pipe  with- 
in reach.  With 
this  principle  there 


Ventilation, — A  simple  way  of  ventilating  a  room  that  has 
a  chimney  in  it  is  the  following : — Make  an  opening  in  the 
chimney  over  the  fireplace,  and  as  near  the  ceiling  as  possible, 
about  9  in.  by  2^^  in.,  then  procure  a  piece  of  perforated  zinc, 
10  in.  by  3  J  in.,  and  a  piece  of  oiled  silk  or  calico  9  in.  by  3 

in.  ;  fasten  the  silk 
or  calico  to  one 
edge  of  the  zinc  by 
sewing  it  through 
the  holes ;  it  will 
then  hang  loose  on 
the  zinc  as  on  a 
hinge,  but  it  will 
not  reach  the  ends 
or  bottom  edge  by 
half  an  inch  ;  now 
fix  the  zinc  over  the  hole,  with  the  flap  inside,  notjjn  the  room, 
and  with  the  edge  that  is  secured  uppermost.  A  strip  of  paper 
bordering  may  be  posted  on  the  wall,  and  partly  on  the  place, 
to  hold  it.  The  up-draft  will  blow  the  silk:  back,  but  the  down- 
draft  of  the  chimney  will  close  it. 

Cheap  and  Effective  Filter. — Procure  one  small,  low,  but 
broad  tree-pot,  and  two  very  large  ones,  both  of  a  size  ;  also  a 
large  deep  water-pot  or  tub,  and  a  supply-cask  or  tub  ;  then 
get  five  or  six  feet  of  gutta-percha  piping,  and  two  small  pieces 
of  the  best  and  finest  sponge,  and  close  up  the  holes  in  the 


I 


HOUSE  AND  GARDEN. 


19] 


large  tree-pots  tightly  with  the  sponges.  Place  one  of  the  tree- 
pots  within  the  other,  so  that  the  sponges  do  not  touch  each 
other;  this  being  done,  and  all  in  readiness  prepared,  the 
sand,  pounded  glass,  or  charcoal  being  thoroughly  washed 
clean  from  dirt  or  dust,  first  put  the  small  tree-pot  into  the 
water-pot  (it  being  previously  raised  upon  some  bricks),  and 
fill  up  the  space  between  the  sides  of  each,  to  the  tree-pot 
brim,  with  sand,  pounded  glass,  or  charcoal  broken  small. 
Now  put  the  two  large  tree-pots  together  into  the  water-pot 
also,  to  rest  upon  the  small  tree-pot,  and  again  fill  up  with 
sand  between  the  outer  tree-pot  and  the  water-pot ;  then  pour 
water  on  the  sand  all  round,  so  that  it  may  find  its  bed  or  level, 
and  repeat  the  sand  and  water  until  the  level  of  the  sand  be 
near  the  top  of  the  water-pot.  You  may  now  put  one  end  of 
the  tube  or  pipe  through  a  hole  made  in  the  upper  part  of  the 
supply-cask,  so  as 
to  nearly  reach  the 
bottom ;  then  draw 
up  the  water  into 
the  pipe  with  the 
mouth,  keeping  the 
end  depressed,  and 
the  syphon  will  be 
in  action,  placing 
the  other  end  in  the 
water-pot.  Your  fil- 
ter being  now  made, 

you  will  soon  obtain  clear  water  from  the  upper  tree-pot,  which 
you  can  lead  out  or  draw  off,  which  is  preferable,  with  another 
short  syphon,  into  a  receiver. 

Having  once  had  need  of  a  filter  we  adopted  a  similar  plan, 
with  charcoal  between  the  two  large  tree-pots,  with  a  piece  of 
flannel  surrounding  the  sides  and  bottom  of  the  upper  tree-pot, 
minus  the  small  pot  and  sand ;  but  in  time  the  flannel  is  apt 
to  rot  and  become  unwholesome. 

C,  the  supply-cask ;  SS,  the  supply-syphon  ;  Z,  the  stool  of 
elevation  for  syphon  action  ;  A,  the  water-pot ;  UV,  the  large 
tree-pots  ;  FW,  filtered  water ;  W,  water  ;  SS,  sand ;  R,  re- 
ceiver of  filtered  water  ;  DS,  discharge  syphon  ;  LLL,  hds  and 
sponges  ;  KK,  bricks  ;  N,  notch  made  in  tree-pot  for  pipe ; 
U,  upper  tree-pot ;  V,  the  lower  one.     As  the  filtered  water  has 


192 


HOUSE  AND  GARDEN. 


to  ascend,  the  action  of  this  filter  is  preferable  to  those  wherein 
it  has  to  descend. 

Hat  and  Cloak  Peg  Frames. — Here  is  a  portable  hat  and 
cloak  peg  frame,  made  either  of  mahogany  or  deal,  framed 
together,  about  3  feet  long  by  6  in.  wide  ;  the  framing  is  i  in. 
wide,  by  |  in.  thick ;  the  pegs  or  hooks,  hinged  between  on  wire 

pins,  are  of  the  same 

0    ■         .0 


mS^HEE 


thickness    as   fram- 
ing ;    the  letters   A 
show    the    rails    of 
framing,    and    it    is 
hung  with  two  rings 
as  shown.      It  is  suitable  for  either  halls,  backs  of  doors,  or 
tents,  and  can  be  removed  at  pleasure.     It  can  be  made  of  any 
length,  and  the  hooks  fold  flat  as  shown. 

Alarums. — From  among  the  many  ingenious  contrivances 


known  as  "  Early  Risers'  Friends,"  "  Mechanics'  Friends,"  &c., 
we  select  the  above  : — 

I.  A  is  the  kitchen,  B  the  bedroom,  and  C  the  clock.      It 


HOUSE  AND  GARDEN. 


193 


does  not  matter  if  your  clock  has  only  one  weight ;  when  the 
clock  is  in  action,  watch  it  for  one  hour ;  notice  how  much  the 
weight  lowers  in  that  time  ;  then  divide  it  into  a  scale  of  halves 
and  quarters  ;  after  which,  mark  on  the  wall  the  hours,  as 
shown  at  D.  When  going  to  bed,  consider  how  many  hours 
you  wish  to  sleep.  Example  :  Supposing  it  to  be  half-past 
ten,  and  you  wish  to  rise  at  five  o'clock,  raise  the  weight  E  to 
half-past  six.  At  five  o'clock  in  the  morning  the  weight  E  will 
press  on  lever  F,  down  drops  weight  G,  pulling  string  HHH, 
and  down  drops  a  heavy  parcel  on  the  legs  of  the  sleeper.  At 
the  same  time  that  weight  I  is  lowering,  round  goes  the  cog- 
wheel K,  pressing  against  the  tin-spring  L,  which  makes  a 
great  noise.  Where  there  may  chance  to  be  a  cupboard,  as  at 
MM,  the  string  can  go  into  it  out  of  sight.  NN  is  a  short 
piece  of  elastic  placed  to  keep  the  string  on  pulleys,  when  the 
weight  G  is  suspended  at  i,  2,  3,  4,  5,  6,  7,  8.  Use  round 
nails  for  wires  to  work  on.  No.  9  screw  to  slack  or  press  the 
tin  on  wheel,  00  nails  to  secure  alarum  to  wall,  P  balance- 
weight  for  I,  and  to  keep  string  on  pulley  Q.  In  addition  to 
the  above,  turn  the 
light  nearly  out  of 
the  lamp  at  night, 
so  that  weight  (I) 
can  put  full  light  on 
in  the  morning  by 
lowering  lever  T. 

2.  A,     lamp ; 

B,  spring  holding 
socket  for  match  ; 

C,  centre  tumbler, 
connecting  the 
spring  to  the  match 
holder;  D,  lever; 
E,  pinion  holding 
the  spring,  having 
a  rough  surface  for 
the  purpose  of  ig- 
niting the  match  ;    F,  whistle  ;    G,  coffee  can^ 

3.  The  following  is  an  apparatus  attached  to  an  ordinary 
alarum  clock.  It  has  been  practically  tried,  and  found  satis- 
factory.     It   is   enclosed   in  a  frame  or  case,  and  suspended 

N 


194 


HOUSE  AND  GARDEN. 


against  a  wall,  just  below  the  ceiling,  so  as  to  give  the  weight 
plenty  of  room  to  run  down.  AB,  arbor,  bearing  a  fly-wheel 
C,  in  which  are  inserted,  in  a  radial  direction,  two  hammers 
DE  ;  these  impinge  on  the  inner  edge  of  a  gong  F,  suspended 


by  a  rod  G.  Round  the  arbor  is  rolled  the  cord  H,  which  is 
acted  upon  by  the  weight  I.  This  weight  is  suspended  in  the 
bight  of  a  cord  N,  and  is  released  on  the  running  down  of  the 
alarum-weight  J,  as  will  be  seen  by  the  engraving. 


Water -Tight   Cisterns. 

— Construct  your  cistern  in 
the  usual  mode — viz.,  the 
sides  nailed  to  the  ends.  It 
can  scarcely  be  made  tight 
by  any  paint  or  cement 
where  the  grain  of  the  wood 
or  end  and  bottom,  of  the  tank  have  a  differ- 


of  end  and  side. 


HOUSE  AND  GARDEN. 


195 


ent  direction,  and  are  fixed  together  with  nails.  The  pieces  so 
joined  are  constantly  sHding  one  on  the  other,  the  one  swelUng 
and  contracting,  and  the  other  not — in  fact,  they  cannot  agree. 
The  following  arrangement  will  obviate  this  : — Secure  sides  to 
bottom,  which  should  both  have  the  grain  of  wood  in  direction 
of  the  arrow.  Fit  the  end  (the  edges  of  which  should  be  like 
those  of  a.  cask-head)  into  groove  G,  and  nail  the  bottom 
of  tank  only  to  the  lower  edge  of  the  end-pieces,  the  end-piece 
to  have  the  grain  up  and  down.  The  ends  of  sides  to  be  drawn 
together  by  two  or  more  screw  bolts  and  nuts  SS.  Thus 
formed,  when  the  sides  swell,  they  have  liberty  by  sliding  on 
the  edge  of  ends  to  expand  or  contract.  If  a  tank  thus  made 
leak,  let  some  pitch  be  melted  into  the  seams  with  a  heated 
ploughshare,  or  any  convenient  piece  of  iron,  the  wood  being 
first  thoroughly  dry. 

Improved  Way  of  Storing  Rain-Water. — When  casks  are 
used  to  catch  rain-water,  holes  are  often  cut  in  the  higher  ones 
to  let  the  water  fall 
into  the  lower.  A 
better  way  would  be 
to  take  a  piece  of 
gas  -  pipe,  bend  it 
into  the  shape  of 
the  letter  U,  and 
fill  it  with  water, 
to  exclude  the  air. 
Put  one  end  into 
each  tub,  the  one 
being  full,  the  other 
empty.  They  will 
soon  come  to  a 
level.  In  this  way 
a  number  of  vessels 
may  be  set  all  upon 
the  level,  without 
cutting  or  boring 
holes. 

G-arden  Engine. — BCEFH  is  a  force-pump  together  with 
an  air-vessel;  BB  is  a  barrel  about  2  in.  diameter  by  10  in. 
long,  made  of  copper  or  brass  (a  piece  of  telescope  tube  would 


196 


HOUSE  Al^D  GARDEN. 


answer  very  well)  screwed  into  the  stand  (iron)  CDEF  ;  H  is 
an  air-vessel ;  I  and  J  are  the  suction  and  delivery  valves  ;  F 
is  the  deliver>'-pipe,  to  which  should  be  attached  a  piece  of 
indiarubber  hose  about  |ths  of  an  inch  in  diameter,  at  the  end 
of  which  is  a  jet  or  nose.     The  piston  is  formed  of  two  leather 

cups,  the  top  one  in- 
verted, which  are 
held  in  their  proper 
position  by  two  col- 
lars to  the  rod.  Dirt, 
&c.,  is  prevented 
from  entering  the 
pump  by  means  of  a 
piece  of  iron  gauze 
represented  by  dots 
beneath  the  nose  D  E. 
As  soon  as  the  handle 
is  raised,  the  water 
enters  the  pump 
through  the  valve  J, 
which  closes  when 
the  lever  is  depres- 
sed. The  water  is 
then  forced  into  the 
air  -  vessel  through 
the  valve  I,  which 
prevents  its  return. 
The  air  in  H  again 
being  compressed,  as 
soon  as  the  power  is 
removed,  forces  the 
water  very  rapidly 
through  the  delivery- 
pipe,  &c.  Should 
the  pail  AAAA  not 
be  required,  the  foot 
of  stand  must  be  larger,  a  piece  of  hose  being  attached  to  DE, 
and  a  stuffing-box  placed  at  the  top  of  the  pump,  to  prevent  the 
escape  of  any  water  that  might  pass  the  plunger. 


Double- Action  Pump  for  Garden  Engine. — By  the  sketch 


DRA  WING  AND  MODELLING. 


197 


^ 


^r 


below,  it  will  be  seen  that  the  water  is  kept  constantly  in  a 
stream  both  with  the  ascent  and  descent  of  the  piston.     The 
sketch  is  so  simple  as  to  require 
no  further  explanation. 

Transfer  Paper. — Transfer 
paper  may  be  prepared  thus : — 
Make  a  mucilage  with  1  oz.  of 
gum  tragacanth;  strain;  add  i 
oz.  of  glue  and  \  oz,  of  gam- 
boge. Mix  French  chalk  4  oz,, 
old  Paris  plaster  J  oz.,  starch 
I  oz.  ;  run  them  through  a 
sieve,  grind  with  the  mixed 
mucilage,  add  water  to  reduce 
to  the  consistence  of  oil,  and 
apply  it  with  a  brush  to  thin- 
sized  paper.  The  drawing  made 
on  this  prepared  side  of  the 
paper  is  wetted  at  the  back  and 
placed  on  the  stone,  which  is  warmed  to  125°  Fahr.  ;  the  whole 
is  then  strongly  pressed  in  the  lithographic  press,  and  the  stone 
receives  the  impression,  which  may  be  printed  from  as  usual. 
When  two  impressions  are  required,  a  red  composition  is  made 
of  wax  2  parts,  soap  i  part,  and  vermillion  to  colour,  all  melted 
in  a  saucepan,  and  ground  with  water  to  the  consistence  of 
cream.  This  is  spread  thinly  on  the  second  stone,  an  impres- 
sion from  the  first  stone  is  next  applied,  and  the  second  draw- 
ing is  thus  made  to  correspond  with  the  first  exactly.  If  in 
printing  the  drawing  becomes  smutty,  mix  equal  parts  of  water, 
olive  oil,  and  oil  of  turpentine  j  shake  till  they  froth,  wet  the 
stone,  throw  this  froth  on  it,  and  rub  it  with  a  soft  sponge. 
The  printing  ink  will  be  dissolved,  and  the  drawing  will  almost 
disappear ;  but,  on  rolling  it,  it  reappears  as  clear  as  at  first. 
When  the  stone  is  laid  by  for  future  use,  a  preserving  ink  is 
applied,  to  prevent  the  surface  printing  ink  becoming  too  hard. 
Thick  varnish  of  linseed  oil  2  parts,  tallow  4  parts,  wax  and 
Venice  turpentine,  of  each  i  part ;  melt ;  add  by  degrees  lamp- 
black 4  parts,  mix  thoroughly,  and  preserve  in  a  tin  case.  This 
must  be  rolled  on  the  stone  each  time  before  laying  it  aside  for 
future  use.     When  the  whole  of  the  impressions  are  completed, 


198  DRA  WING  AND  MODELLING. 

and  the  stones  required  for  other  drawings,  two  of  the  stones 
are  laid  face  to  face,  and  ground  with  sand  and  water  until  the 
surfaces  are  clear.  They  are,  finally,  more  or  less  polished 
with  pumicestone,  according  to  the  required  fineness,  and  are 
then  prepared  to  receive  other  drawings. 

Tracing- Paper. — Having  prepared  a  mixture  of  equal  parts 
of  turpentine  and  gum-mastic,  spread  out  a  number  of  sheets 
of  crown'  tissue-paper,  one  over  the  other ;  then  brush  the  top 
sheet  over  with  the  above  mixture,  and  hang  it  up  to  dry. 
Proceed  with  the  rest  in  same  manner.  As  the  under  sheets 
absorb  some  of  the  varnish  laid  on  those  above  them,  less  will 
be  used  than  if  each  was  brushed  separately.  This  varnish  for 
tracing-paper  leaves  the  paper  quite  light  and  transparent.  It 
may  readily  be  written  on,  and  drawings  traced  with  a  pen  are 
permanently  visible.  It  is  used  by  learners  to  draw  outlines. 
The  paper  is  placed  on  the  drawing,  which  is  clearly  seen,  and 
an  outline  is  made,  taking  care  to  hold  the  tracing-paper  steady. 
In  this  way  elaborate  drawings  are  easily  copied. 

Oiling  Tissue-Paper. — Lay  it  on  a  flat  surface,  and  rub 
linseed  oil  over  it  with  a  piece  of  cotton  wool  or  a  brush,  and 
hang  it  up  to  dry. 

Stencil-Plates . — For  cutting  stencil-plates  use  a  mixture 
of  3  parts  nitric  acid  and  i  part  water.  After  heating  the 
plate  slightly,  prepare  the  ground  for  etching  by  rubbing  it  over 
with  common  heel-ball.  The  back  of  the  plate  should  be  oiled, 
so  that  the  cutting  may  be  clean. 

Drawing-Board,  to  Black. — Take  \  lb.  of  lampblack,  and 
put  it  on  a  fire-shovel  over  a  clear  fire  until  it  is  red  hot ;  then 
take  it  off,  and,  when  cool,  pound  it  very  fine,  and  mix  it  with 
a  pint  of  turpentine.  This  should  be  laid  on  with  a  size-brush. 
If  the  board  is  new,  before  using  the  above  it  will  be  necessary 
to  give  it  one  or  two  coats  of  lampblack  mixed  with  boiled  oil. 

Map  Colouring.  —  Ordinary  water-colour  paints  may  be 
used,  preferring  the  moist  variety,  and  those  not  opaque,  such 
as  gamboge,  carmine,  indigo,  or  Prussian  blue.  With  these 
all  the  colours  required  may  be  formed.  Wet  the  sheets  with 
clean  water  first,  and  as  soon  as  the  moisture  has  disappeared 
from  the  surface,  apply  a  thin  wash  of  the  colour  with  a  toler- 
ably full  brush,  passing  over  the  surface  quickly.      Commence 


DRAWING  AND  MODELLING.  199 

at  the  top  and  at  his  left  hand,  coming  down  to  the  bottom 
right  hand.  Use  blotting-paper  to  dry  any  superabundance  of 
colour. 

Pencil  Drawings,  to  Preserve. — Apply  a  thin  wash  of 
isinglass,  which  will  prevent  rubbing  off  either  of  black  lead,  or 
of  hard  black  chalk. 

Pencil  Writing,  Indelible. — Some  years  ago  the  Society  of 
Arts  offered  a  premium  for  an  indelible  pencil  to  write  on  com- 
mon paper,  but  nothing  satisfactory  was  produced.  Any  pencil 
writing  or  drawing  may,  however,  be  rendered  as  indelible  as 
if  performed  with  ink  by  the  following  simple  process  : — Lay 
the  writing  or  drawing  in  a  shallow  dish,  and  pour  skimmed 
milk  upon  it.  Any  spots  not  wet  at  first  may  have  the  milk 
placed  over  them  lightly  with  a  feather.  When  the  paper  is 
all  wet  over  with  the  milk,  take  it  up  and  let  the  milk  drain 
off,  and  whip  off  with  the  feather  the  drops  which  collect  on 
the  lower  edge.  Dry  carefully,  and  it  will  be  found  to  be  so 
perfectly  indelible  as  not  to  be  removed  even  with  indiarubber. 

Picture  -  Cleaning. — The  most  simple  application  for  oil 
pictures  is  water  and  plenty  of  it.  If  the  coats  of  varnish  are 
very  thick,  the  scraper  may  remove  a  good  deal.  Spirits  of 
wine  and  turpentine  may  be  applied  ;  but  the  scraper,  spirits  of 
wine  and  turpentine,  will  attack  the  paint  as  well  as  varnish, 
and  the  art  of  picture-cleaning  is  to  stop  action  before  you 
arrive  at  the  paint.  Water  will  stop  further  action  of  the 
spirits.  Experimentalize  only  on  a  corner  or  an  unimportant 
part  of  a  picture.  Many  good  and  valuable  pictures  have  been 
rendered  worthless  by  the  process  of  what  is  usually  called 
cleaning,  particularly  under  the  infliction  of  spirits  of  wine, 
turpentine,  home-made  varnish,  &c.  If  the  picture  be  an  old 
one,  it  is  usual  to  begin  by  rubbing  off  the  old  varnish,  which 
is  done  with  the  fingers,  rubbing  gently  and  evenly  in  small 
circles  over  the  whole  picture,  beginning  with  a  little  dust  on 
the  fingers,  after  which  the  light  powder — the  remains  of  the 
gum  of  the  old  varnish  — will  soon  appear.  Care  must  be 
taken  not  to  touch  the  colour  of  the  picture.  Then  wash  with 
clear  water,  and  when  quite  dry,  varnish.  It  is  preferable  in 
all  respects  to  buy  varnish  at  the  artist's  colour-shops.  If  there 
is  not  any  old  varnish  on  the  old  picture,  first  wash  the  picture 


DRA  WING  AND  MODELLING. 


with  warm  rain-water,  using  a  soft  sponge,  and  then  carefully 
with  a  lukewarm  solution  of  a  quarter  pound  of  soft  soap  in  a 
quart  of  rain-water. 

Varnishes  for  Prints  and  Water-Colour  Drawings. — The 

printing  must  be  thoroughly  dry.  Size  made  by  boiling  an  ounce 
of  best  isinglass  in  a  pint  of  water  should  then  be  applied  quickly 
to  the  surface.  This  may  be  done  in  two  ways,  the  latter  being 
preferable.  First  brush  the  size  over  the  surface  of  the  picture 
rapidly  with  a  broad  camel's-hair  brush  ;  second,  having  poured 
the  solution  into  a  flat  dish,  pass  the  drawing  quickly  through 
the  fluid,  so  that  the  whole  of  both  surfaces  may  be  thoroughly 
wetted.  Lay  the  drawing  carefully  upon  a  flat  board  to  dry ; 
any  colourless  varnish  may  then  be  applied.  If  isinglass  can- 
not be  procured,  clear  gum-water  will  answer  almost  as  well. 

A  good  and  cheap  Varnish  for  general  use,  and  one  which 
dries  in  a  very  short  time,  may  be  made  of  the  best  wood 
naphtha  i  pint,  gum  shellac  2  oz.,  gumsandarac  2  oz.  ;  pound 
the  ingredients  in  a  mortar,  and  pour  on  the  naphtha,  shaking 
it  up  often.  When  dissolved,  filter  through  fine  muslin,  and 
the  varnish  will  then  be  fit  for  use.  If  too  thick,  add  more 
naphtha. 

A?iother  Varnish^  fitted  for  prints  or  drawings,  is  the  follow- 
ing : — Give  the  article  one  or  two  coats  of  gum  arable,  dissolved 
in  water,  about  2  oz.  to  a  pint ;  a  coat  of  crystal  varnish  will 
complete  the  operation.  The  crystal  varnish  may  be  purchased 
at  any  of  the  oil  and  colour  shops.  Turpentine  varnish  is 
often  used  in  lieu  of  crystal,  and  is  much  cheaper.  Fine 
parchment  size,  or  isinglass,  will  be  found  preferable  to  gum- 
water.  The  best  varnish  is  clear  pale  copal,  dissolved  in  recti- 
fied spirit,  which  is  easily  done  by  heat.  A  small  quantity  of 
shellac  will  harden  the  varnish,  but  it  communicates  a  brown- 
ish tinge.  A  varnish  composed  of  shellac  alone,  dissolved  in 
spirit,  is  so  hard,  that  if  a  coat  of  it  be  laid  upon  a  card,  it  may 
be  written  upon  with  a  pen  and  ink,  and  rubbed  out  again  with 
a  sponge,  without  leaving  any  perceptible  trace. 

Another  Varnish. — Balsam  of  copaiba  4  parts,  powdered 
copal  I  part.  Mix,  and  keep  it  in  a  close  vessel  at  a  heat  of 
150°  Fahr.,  until  the  gum  is  dissolved;  then  thin  it  with  tur- 
pentine. 

Size  for  Prints  or  Drawings  before  Colouring. — Best  pale 


DRA  WING  AND  MODELLING. 


glue  and  white  soap,  of  each  2  oz.,  hot  water  30  oz. ;  dissolve, 
and  add  powdered  alum  i  oz. 

Painters'  Cream. — Painters  who  have  long  intervals  between 
their  periods  of  labour  are  accustomed  to  cover  the  portions 
painted  with  a  preparation  which  preserves  the  freshness  of  the 
colours,  and  which  can  be  removed  when  they  resume  their 
work.  This  is  the  preparation  : — Take  of  clear  nut  oil  3  oz.  ; 
mastic  in  tears,  pulverized,  \  oz.  ;  sal  saturni,  in  powder,  ace- 
tate of  lead,  j  oz.  Dissolve  the  mastic  in  oil  over  a  steady- 
fire,  and  pour  the  mixture  into  a  marble  mortar  over  the 
pounded  salt  of  lead  ;  stir  it  with  a  wooden  pestle,  and  add 
water  in  small  quantities  till  the  matter  assumes  the  appear- 
ance and  consistence  of  cream,  and  refuses  to  admit  more 
water. 

Modelling. — Rice  flour,  mixed  thick  with  a  little  cold  water, 
and  warmed  over  a  fire,  may  be  moulded  into  busts,  figures, 
bas-reliefs,  ornaments,  &c.,  very  readily.  When  dry  and  hard, 
images  thus  formed  may  be  polished,  and  will  be  found  very 
durable. 

Gypsum  —  Plaster  of  Paris.  —  This  substance  possesses 
some  peculiar  properties.  It  consists  of  sulphuric  acid,  lime, 
and  water;  its  composition,  or  rather  the  proportion  of  its 
component  parts,  being  similar  to  that  of  alabaster.  Its  abund- 
ance in  the  tertiary  basins  around  Paris  has  given  it  the  name 
of  plaster  of  Paris.  It  is  found  in  Nova  Scotia  in  profusion  in 
the  lower  carboniferous  rocks.  It  is  produced  by  the  decom- 
position of  iron  pyrites  and  limestone  in  juxtaposition.  It  is 
formed  wherever  sulphuric  acid  is  generated,  and  comes  in 
contact  with  carbonate  of  lime.  Crystallized  gypsum  is  called 
selenite,  and  the  ancient  Romans  are  said  to  have  used  it  as 
glass.  It  is  often  coloured  by  oxide  of  iron  to  grey,  brown, 
red,  yellow,  and  even  black.  It  is  used  extensively  for  making 
plaster  casts,  and  for  stucco.  It  is  prepared  for  these  purposes 
by  calcining,  which  is  simply  heating  it  in  kilns  or  kettles  until 
the  water  is  expelled.  It  is  then  a  fine  powder,  like  wheat 
flour,  and  to  be  used,  must  have  the  water  which  it  previously 
held  returned  to  it.  To  preserve  it  from  contracting  the  mois- 
ture in  the  atmosphere,  it  should  be  kept  as  nearly  air-tight  as 
possible.     Much  of  the  plaster  or  gypsum  sold  in  the  market 


202  DRA  WING  AND  MODELLING. 

is  deteriorated  by  careless  handling  and  packing.  When  mixed 
with  water,  it  "  sets  "  quickly,  and  no  time  should  be  lost  be- 
tween the  mixture  of  the  gypsum  and  the  taking  of  the  cast. 
Of  late  years  it  has  been  a  favourite  substance  with  dentists 
in  taking  casts  of  mouths  to  which  teeth  were  to  be  fitted.  We 
know  of  no  way  by  which  this  substance,  being  once  used,  can 
be  brought  to  its  original  state.  It  is  used  to  some  extent  in 
glazing  porcelain  ;  but  it  is  more  largely  used  as  a  fertilizer  of 
soils  than  for  any  other  purpose.  Containing  a  large  propor- 
tion of  sulphate  of  lime,  it  is  extensively  used  as  a  manure.  It 
is  excellent  for  grass  of  all  kinds,  furnishing  just  the  nutriment 
needed. 

Fictile  Ivory. — This  ivory  is  prepared  by  intimately  mixing 
and  passing  through  a  fine  sieve  superfine  plaster  of  Paris  and 
Italian  yellow  ochres — half  an  ounce  of  the  latter  to  every  pound 
of  the  former,  and  then  forming  a  plaster  cast  of  these  ingre- 
dients in  the  usual  way.  This  cast  is  first  dried  in  the  open 
air,  and  then  carefully  in  an  oven  ;  after  which  it  is  soaked  for 
1 5  minutes  in  a  mixture  consisting  of  equal  parts  white  wax, 
spermacetti,  and  stearine,  heated  a  little  above  the  melting- 
point.  When  removed  from  this,  the  cast  is  allowed  to  drain, 
and  before  it  is  cold  any  excess  of  the  wax,  &c.,  which  may 
remain  in  the  crevices,  is  brushed  off  by  means  of  a  painter's 
sash-tool ;  and  as  soon  as  it  is  quite  cold,  it  is  polished  with 
a  tuft  of  cotton  wool. 

Plastic  Moulding  {Parkes'  Patent). — To  make  about  i  lb. 
of  this  compo,  melt  together  \  lb,  each  of  wax  and  deer's  flat ; 
then  dissolve  19  or  20  grains  of  phosphorus  in  300  grains  of 
bisulphide  of  carbon.  Keep  the  wax  mixture  barely  melted, 
and  add  the  phosphorus  solution  slowly  to  it.  Briskly  stir  the 
fat  while  pouring  it  in  at  the  bottom  of  the  melted  mixture  by 
means  of  a  vessel  with  a  long  spout  to  prevent  it  inflaming. 
It  is  highly  dangerous  to  spill  the  phosphorus  compo  where  it 
can  come  in  contact  with  wood,  paper,  rags,  &c.,  as  after  a 
lapse  of  even  many  hours  they  will  often  burst  into  flame. 

Vegetables,  Insects,  Small  Birds,  Frogs,  Fish,  &c.,  Cast 
in  Plaster  Moulds. — Provide  a  trough  of  boards,  nailed  to-' 
gether  so  as  not  to  let  the  water  run  through  the  joints  ;  sus- 
pend  in  the  trough,   by  thread  or   Holland  twine,  in  several 


PHO  TO  GRAPH Y.  203 


places,  the  vegetable,  plant,  insect,  &c.,  which  you  would  cast, 
which,  being  performed,  mix  4  parts  of  plaster  of  Paris,  and 
2  parts  of  fine  brick-dust  with  common  water,  to  the  consist- 
ence of  cream,  and  with  this  cover  the  thing  intended  to  be 
cast,  observing  not  to  distort  it  by  any  means  from  its  natural 
position.  When  you  have  filled  your  trough,  let  it  harden  by 
placing  it  near  the  fire  by  degrees  till  you  can  make  it  red  hot ; 
then  let  it  cool,  and  with  a  pair  of  bellows  blow  and  shake  as 
much  of  the  ashes  out  of  the  mould  as  you  can.  You  must 
now  put  a  small  quantity  of  quicksilver  into  the  mould,  and 
shake  it,  in  order  to  loosen  every  part  of  the  ashes  therein  ; 
also  to  make  a  passage  through  where  the  strings  were  tied,  in 
order  to  let  the  air  out  when  you  pour  in  your  metal. 

Metal  for  the  above  Work. — Take  of  grain  tin  6  oz.,  bismuth 
2  oz.,  and  lead  3  oz.  Melt  them  together  in  an  iron  ladle,  and 
you  may  cast  in  the  above  mould  to  your  satisfaction.  You 
may  combine  the  above  ingredients  in  such  proportions  as  to 
compose  a  metal  that  will  melt  in  boihng  water,  thus — Sir 
Isaac  Newton's  fusible  metal  is  composed  of  8  parts  bismuth, 
5  parts  lead,  and  3  parts  tin  ;  this  alloy  melts  at  212°.  Rose's 
alloy  is  still  more  fusible  ;  it  is  2  parts  bismuth,  i  part  lead, 
and  I  tin,  and  melts  at  201°.  Dr  Dalton's  fusible  alloy — 3 
parts  tin,  5  parts  lead,  \o\  parts  bismuth — melts  at  197°. 
The  addition  of  a  little  mercury  makes  it  more  fusible,  and  fits 
it  to  be  used  as  a  coating  to  the  insides  of  glass  globes. 

Varnishing  Plaster  Casts. — Plaster  casts  can  be  varnished 
by  a  mixture  of  soap  and  white  wax  in  boiling  water.  A  \  oz. 
of  soap  is  dissolved  in  a  pint  of  water,  and  an  equal  quantity 
of  wax  afterwards  incorporated.  The  cast  is  dipped  in  this 
liquid,  and,  after  drying  a  week,  is  polished  by  rubbing  with 
soft  linen,  producing  a  polish  like  marble.  If  to  be  exposed  to 
the  weather,  saturate  the  casts  with  linseed  oil,  mixed  with 
w^ax,  or  resin  may  be  combined.  In  casting  the  plaster,  use 
spring-water  and  gum  arable. 

To  Print  on  Canvas. — Prepare  the  canvas  by  washing  it 
over  with  a  solution  of  bicarbonate  of  soda  in  water,  and  rub 
it  until  it  is  evenly  wet.  Wash  with  water  to  remove  the  soda, 
and  then  lay  a  piece  of  albumen  paper,  of  the  size  you  wish  to 
make  the  print,  face  down  upon  it,  and  rub  it  well  to  secure 
contact  all  over.      Lift  up  the  paper  and  remove  the  bubbles. 


204  PHOTOGRAPHY. 


if  there  should  be  any,  with  a  brush.  After  drying,  coagulate 
the  albumen  by  pouring  on  some  strong  alcohol ;  dry  again, 
silver  with  a  40-grain  silver  solution,  slightly  acid  ;  print,  and 
fix  in  hypo. 

Cyanide  of  Silver. — Break  up  an  old  silver  coin,  say  6d. ; 
put  it  into  a  porcelain  cup,  and  cover  it  with  nitric  acid  un- 
diluted ;  set  it  on  a  fire-shovel  over  a  slow  fire,  or  make  it  warm 
by  any  convenient  means,  and  the  silver  will  soon  dissolve ; 
add  acid  occasionally,  if  necessary ;  when  dissolved,  fill  the  cup 
nearly  full  with  clean  rain-water,  and  let  it  settle  for  a  few 
minutes.  Pour  off"  the  clear  liquor  into  a  pint  glass  tumbler  or 
jug,  add  a  tablespoonful  of  clean  common  salt,  chloride  of  silver 
will  be  the  result.  Pour  off"  the  clear  liquor  (which  may  be 
thrown  away),  add  water  to  the  precipitate,  and  agitate  it  well 
with  a  glass  rod,  but  by  no  means  with  a  metal  one ;  pour 
away  the  liquor  as  before ;  wash  again  ;  by  these  means  the 
salt  will  be  washed  out.  Now  dissolve  \  oz.  of  cyanide  potas- 
sium in  a  half  gill  of  rain-water  warm ;  when  dissolved,  and 
the  liquor  cold,  add  it  gradually  to  the  dissolved  silver,  and  a 
good  plating  liquid,  consisting  of  the  double  cyanides  of  silver 
and  potassium,  will  be  the  result.  To  use  the  solution,  clean 
the  article  well,  immerse  in  the  solution  in  contact  with  a  small 
piece  of  clean  zinc.  With  nitrate  of  silver  he  can  proceed 
thus  :  Dissolve  the  crystals  in  water,  add  to  the  solution  gra- 
dually the  solution  of  potassium,  till  a  precipitate  has  fallen, 
then  add  more  cyanide  until  that  precipitate  is  redissolved, — 
a  much  cleaner  way  than  the  others,  and  something  purer  too, 
but  not  so  cheap. 

Instantaneous  Photography. — Herr  Metzger  is  of  opinion 
that  success  in  instantaneous  photographs  depends  more  upon 
the  excellence  of  the  apparatus  and  chemicals  employed,  and 
rapidity  of  manipulation,  than  on  the  practice  of  any  particular 
theory  or  process.  Of  the  many  descriptions  of  collodion,  that 
prepared  according  to  Dr  Liesegang's  formula  appears  to  him 
best  suited  for  instantaneous  photography ;  for  although  (he 
says),  I  have  been  successful  in  obtaining  good  results  with 
mixed  collodions,  I  prefer  to  use  a  material  freshly  prepared, 
together  with  a  neutral  10  per  cent,  silver  bath.  For  develop- 
ing I  employ  the  following  formula,  adding  as  much  alcohol  as 


PHO  TO  GRAPHY.  205 


may  be  necessary  to  make  the  solution  flow  evenly  over  the 
plate,  viz.  : — 

Water,  .  .  .  .  .100  grains. 

Sulphate  of  iron,  .  .  .  .  5      ?? 

Acetic  acid,  .         .         .  .  35? 

My  negatives  are  intensified  with  pyrogallic  acid,  which  is  used 
very  carefully,  in  order  that  the  harmony  of  the  pictures  may 
not  be  destroyed.  The  plate  should  be  exposed  as  soon  as 
possible  after  its  exit  from  the  silver  bath,  and  developed 
immediately  after  exposure ;  the  object  to  be  photographed 
must  be  lighted  as  strongly  as  possible  ;  and  if  direct  sunlight 
is  not  present,  all  false  lights  and  reflections  are  to  be  carefully 
avoided.  March  and  October  are  the  most  favourable  months 
for  instantaneous  photography. 

Instantaneous  Pictures  by  Artificial  Light. — Mr  Thomas 
Skaife  has  patented  a  process  to  obtain  an  instantaneous  flash 
of  artificial  light  for  the  production  of  small  portraits.  The 
specification  is  as  follows  : — These  improvements  relate  to  the 
construction  of  an  apparatus  for  igniting  and  burning  any 
powder  or  other  composition  either  in  a  solid  or  hquid  state,  the 
flame  or  flash  of  which,  being  sufficiently  actinic,  is  applied  for 
the  production  of  photographic  pictures.  For  this  purpose  the 
said  apparatus  consists  of  a  platform  of  metal  or  other  incom- 
bustible substance  perforated  with  one  or  more  touch-holes 
fixed,  attached  to,  or  supported  by,  a  spring  or  springs  in  such 
a  manner  as  to  permit  of  its  being  easily  vibrated  or  thrown 
into  a  tremulous  motion  by  the  touch  of  the  finger  or  other 
appliance.  Connected  with  or  attached  to  the  platform  is  a 
parabolic  or  other  reflector  pierced  with  a  groove,  through 
which  communication  is  made  with  one  end  of  the  platform, 
by  which  it  may  be  touched  or  struck,  so  that  by  means  of  the 
aforesaid  springs  it  may  suddenly  vibrate.  The  deflagrating 
powder  or  other  explosive  actinic  substance,  being  placed  or 
strewn  upon  the  perforated  platform,  is  suddenly  brought  into 
contact  with  a  light  from  an  ordinary  spirit-lamp,  or  such  like 
substance,  preferably  placed  underneath  it;  at  the  same  instant 
the  platform,  being  thrown  into  vibration,  communicates  this 
motion  to  the  particles  of  the  powder  or  other  substance  to  be 
ignited,  the  result  of  which  action  is  that  every  particle  explodes 


2o6  PHO  TO  GRAPHY. 


or  is  ignited  simultaneously,  and  producing  a  flash  of  light 
which,  acting  upon  a  sensitized  plate  in  an  ordinary  camera, 
produces  the  picture  of  any  object  placed  before  it.  When  the 
picture  of  a  near  object  is  required,  the  powder  may  be  placed 
over  a  touch-hole  ;  if  the  picture  of  a  distant  object  is  to  be 
taken,  then  the  powder  may  be  distributed  over  the  platform 
and  over  several  touch-holes,  to  all  of  which  the  light  may  be 
applied.  Having  now  described  the  nature  of  my  invention, 
and  the  principles  by  which  it  is  carried  out  in  practice,  I  wish 
it  understood  that  what  I  claim  and  desire  secured  to  me  by 
the  before  in  part  recited  letters  patent  is,  the  use  of  a  vibrat- 
ing platform  or  table  with  or  without  a  reflecting  mirror,  for  the 
purpose  of  producing,  by  means  of  vibration  among  its  particles, 
an  instantaneous  combustion  of  any  actinic  powder  or  other 
deflagrating  or  easily  flammable  substance,  when  used  for  the 
purpose  of  obtaining  photographic  pictures  substantially  as 
herewithin  described  and  set  forth. 

Photographometer. — This  apparatus  is  intended  to  record 
the  angular  position  of  objects  situated  around  a  given  point. 
It  is  automative,  and  very  simple.  The  record  is  made  by 
photography,  and  the  camera  used,  with  the  exception  of  cer- 
tain additions,  does  not  difler  much  from  the  ordinary  kind. 
The  objective,  which  is  that  usually  employed  by  photographers, 
is  mounted  vertically  on  a  circular  platform  capable  of  rotating, 
by  means  of  clockwork,  in  a  horizontal  plane. .  The  picture  is 
formed,  not  in  a  vertical  plane,  as  in  ordinary  cases,  but  in  a 
horizontal ;  and  therefore  the  rays,  passing  in  through  the  ob- 
jective, are  deflected  90°  by  means  of  a  reflecting  prism,  so  as 
to  fall  on  the  sensitive  surface,  which  is  collodionized  glass, 
and  is  placed  in  such  a  way  that  its  centre  corresponds  with 
the  point  at  which  the  centre  point  of  the  diaphragm  would  be 
represented.  To  prevent  a  number  of  confused  images,  super- 
imposed on  each  other,  being  formed  during  the  rotation  of  the 
objective,  an  opaque  screen,  having  a  narrow  oblong  opening, 
the  medial  line  of  which  passes  through  the  axis  of  rotation, 
is  placed  over  the  whole  of  the  sensitized  surface,  and  revolves 
along  with  the  objective.  The  result  of  this  arrangement  is 
the  production  on  the  sensitized  plate  of  images  of  the  different 
points  that  lie  around  the  observer  ;  the  angles  formed  by  lines 
joining  the  centre  of  the  plate,  and  the  different  objects  being 


PHOTOGRAPHY.  207 


exactly  the  same  as  those  formed  by  lines  joining  the  centre  of 
the  instrument  and  the  objects  themselves.  The  position  of 
the  objects  thus  accurately  obtained  may  be  transferred  to 
paper,  &c.,  in  the  ordinary  way.  As  different  velocities  of 
rotation  may  be  suited  to  different  purposes,  three  different 
velocities  may  be  obtained  by  means  of  a  regulator.  And  as 
it  may  be  wished  to  mark  down  only  certain  points  of  the 
panorama,  an  arrangement  is  made  which  secures  the  attain- 
ment of  this  object.  Should  it  be  desired  to  observe  not 
different  points,  but  successive  changes  at  the  same  point,  the 
objective  and  the  screen  are  disconnected,  so  that  only  the 
latter  revolves  ;  the  successive  appearances  at  the  same  point 
are  then  recorded  in  succession  in  a  circle  round  the  sensitized 
plate. 

Hyposulphite  of  Ammonia  for  Fixing. — The  question  has 
repeatedly  been  asked  as  to  whether  the  use  of  hyposulphite  of 
ammonia  might  not  be  found  more  efficient  in  fixing  than  that 
of  the  soda  salt.  In  some  of  Sir  John  Herschel's  earhest  ex- 
periments with  the  hyposulphites  as  solvents  for  silver  salts, 
he  used  hyposulphite  of  ammonia,  but  we  have  no  record  of  its 
use  for  photographic  purposes.  Mr  T.  H.  Redin,  a  skilful 
amateur  photographer,  has  made  some  good  prints  fixed  with 
hyposulphite  of  ammonia.  It  was  used  in  the  same  manner  as 
the  soda  salt.  There  is  good  reason  to  believe  it  will  be  valu- 
able in  securing  more  perfect  fixation  than  has  hitherto  been 
secured,  and  will  so  be  conducive  to  permanency.  Hyposul- 
phite of  soda  does  not  perfectly  dissolve  albuminate  of  silver, 
but  leaves  some  portion  of  the  silver  salt  in  the  whites  of  the 
print.      The  new  salt  effects  the  perfect  removal  of  the  silver. 

Recovering  Silver. — Let  the  amateur  put  his  powder,  sand 
and  all,  into  a  glass  or  earthenware  jar,  and  pour  over  it  some 
aquafortis,  diluted  with  seven  times  its  bulk  of  water,  consider- 
ably more  than  enough  to  cover  the  sand,  &c.  Stir  well  with 
a  glass  rod  or  piece  of  charcoal  or  wood,  so  long  as  any  fumes 
are  given  off.  Allow  it  to  settle,  and  pour  off  the  clear  ;  what 
remains  as  sediment  may  be  thrown  out,  as  it  is  only  sand  and 
dirt,  the  silver  and  copper  being  dissolved  out.  To  the  blue 
liquid  portion  add  muriatic  acid  (spirit  of  salt)  so  long  as  a 
white  curdy  precipitate  is  formed  and  falls.  Pour  off  the  liquid 
portion,  and  throw  it  away  as  useless.     Wash  the  precipitate 


2o8  PHOTOGRAPHY. 


frequently  with  water  until  it  is  tasteless,  or  is  in  no  way  acid, 
without  losing  any.  Then  dry  it  at  a  low  temperature  unex- 
posed to  light.  The  remaining  powder  is  tolerably  pure 
chloride  of  silver.  If  it  is  desired  to  obtain  metallic  silver 
from  this,  the  chloride,  the  following  process  is  both  elegant 
and  extremely  simple  : — Put  the  chloride  of  silver  into  a  glass 
tumbler  with  some  slips  or  chippings  of  thin  sheet  zinc.  Then 
add  some  oil  of  vitriol  diluted  with  seven  times  its  bulk  of 
water,  sufficient  to  saturate  and  cover  the  contents  of  the  glass, 
stir  with  a  slip  of  sheet  zinc  until  the  contents  assume  a  homo- 
geneous grey  colour.  Remove  the  clippings  of  zinc,  and  wash 
the  remaining  powder  with  water  until  it  ceases  to  be  acid  ; 
dry  it,  and  what  remains  is  chemically  pure  metallic  silver.  If 
wanted  in  a  solid  condition,  fuse  it  in  a  crucible  with  a  little 
powdered  charcoal,  when  it  will  assume  the  brilliant  white 
metallic  lustre  characteristic  of  the  pure  metal.  If  he  wishes 
for  the  alloyed  metal  he  has  lost,  he  may  get  it  in  a  much 
simpler  way.  Let  him  precipitate  the  powder  into  a  shallow 
glass  or  earthenware  vessel  full  of  water.  The  metal  being  the 
heaviest  will  fall  to  the  bottom  first.  By  removing  the  super- 
ficial layer  of  sand  and  dirt,  and  repeating  the  process  several 
times,  he  will  obtain  the  lost  metal  composed  most  likely  of  a 
mixture  of  silver  and  copper. 

Silver,  How  to  Save. — The  waste  silver  is  an  item  of  con- 
siderable importance  to  every  photographer,  and  an  apparatus 
for  saving  it  must  therefore  be  useful.  A  "  Practical  Photo- 
grapher "  thus  explains  his  plan  : — I  made  my  sink  with  more 
dip  or  inclination  from  horizontal  than  is  usual,  in  order  to 
have  the  water  flow  off  more  rapidly  ;  then  in  the  lowest  corner 
I  inserted  two  lead  pipes  close  together,  one  of  them  leading 
into  the  waste  drain,  the  other  into  a  tank  or  barrel  under  the 
sink,  which  should  be  of  sufficient  size  to  contain  the  washings 
of  one  day's  work.  These  vents  can  be  opened  or  closed  at 
pleasure,  by  moving  a  lever  attached  in  such  a  manner  as  to 
close  one  while  it  opens  the  other,  and  vice  vejsd  ;  or  the  pipe 
may  be  simply  closed  with  a  cork,  which  can  be  shifted  from 
one  to  the  other  as  is  desired.  This  is  not  so  convenient  a 
method  as  the  other.  Whenever  the  washings  contain  silver 
or  gold,  I  allow  them  to  pass  into  my  tank ;  but  when  worth- 
less, by  shifting  my  lever  I  let  them  run  to  waste.     I  have  a 


PHOTOGRAPHY.  209 

faucet  inserted  into  the  tank  about  one  foot  from  the  bottom^ 
and  after  the  day's  work  is  over,  I  draw  off  two  or  three  gallons 
of  the  contents  of  the  tank,  and  add  to  it  sufficient  cream  of 
lime  or  whitewash  to  neutralise  the  whole,  and  pour  it  back. 
If  this  operation  is  rightly  managed,  the  water  can  be  drawn 
from  the  tank  perfectly  clear  after  standing  over  night.  The 
cream  of  lime  is  best  prepared  by  selecting  the  purest  lumps 
of  quicklime,  and  slacking  them  carefully  with  boiling  water 
(sufficient  water  should  be  added,  and  the  mass  constantly 
stirred,  to  prevent  its  getting  too  hot  or  dry  in  spots,  in  which 
case  it  will  be  lumpy  and  coarse) ;  after  cooling,  it  should  be  of 
the  consistence  of  thick  cream,  and  may  be  kept  in  an  earthen 
or  stone  jar  for  a  long  time,  if  properly  covered,  so  as  to  protect 
it  from  the  carbonic  acid  of  the  air.  It  will  be  found  very 
convenient  for  many  purposes.  As  fast  as  the  tank  fills  up 
with  sediment  to  the  faucet,  I  dip  it  out  and  dry  it,  and  reduce 
the  silver  by  any  method  that  may  be  preferred.  The  opera- 
tions are  easy  and  economical,  and  the  saving  of  silver  con- 
siderable. 

To  use  Old  Baths,  and  Save  the  Silver. — A  correspondent 
of  the  American  Journal  of  Photography  says — "  For  several 
months  past  I  have  been  using  an  old  silver  bath  for  silvering 
albumen  paper.  It  had  been  used  a  long  time,  and  was  in 
such  a  condition  that  it  would  not  work  without  considerable 
trouble,  so  I  added  pure  water  sufficient  to  precipitate  the 
iodide  ;  then,  after  filtering,  I  added  silver  in  crystals  until  the 
solution  was  strong  enough  for  silvering  paper  ;  then  a  sufficient 
quantity  of  aqua  ammonia.  It  seems  to  give  as  good  results 
as  to  use  the  crystals.  There  is  more  economy  in  this  process 
than  in  '  doctoring  up '  an  old  bath  ;  for  any  one  who  makes 
photographs  uses  more  silver  for  silvering  paper  than  for  any 
other  purpose,  and  by  this  process  old  baths  that  '  will  not 
work'  can  be  used  up." 

Nitrate  of  Silver  Bath  for  Negatives,  Preparation  and 
Management  of. — This  bath,  which  exercises  such  an  impor- 
tant influence  on  the  quality  of  photographs,  is  simply  composed 
of  nitrate  of  silver  dissolved  in  water.  When  dissolved,  it 
should  be  nearly  neutral,  the  deviation  from  neutrality  being  in 
favour  of  acidity.  In  much  of  the  nitrate  of  silver  of  commerce 
there   is   imprisoned  a  certain  quantity  of  nitric  acid,  which, 


PHOTOGRAPHY. 


when  the  crystals  are  dissolved  in  distilled  water,  renders  the 
solution  acid  in  top  great  a  degree.  If  the  ordinary  commer- 
cial crystals  be  employed,  crush  them  into  a  coarse  powder  and 
apply  heat,  which  drives  off  the  excess  of  nitric  acid.  Then 
dissolve  them  in  distilled  water,  in  the  proportion  of  35  grains 
of  the  crystals  to  i  oz.  of  water.  Use  only  half  of  the  water 
intended  to  be  added,  and  then  add  (previously  dissolved  in  a 
small  quantity  of  water)  about  3  grains  of  iodide  of  potassium. 
The  iodide  of  silver  formed  by  this  addition  will  be  dissolved, 
after  which  add  the  remaining  half  of  the  water,  and  then  filter. 
With  most  of  the  samples  of  nitrate  of  silver  no  other  prepara- 
tion is  required.  If,  however,  the  picture  taken  prove  deficient 
in  clearness,  add  one  or  two  drops  of  a  very  diluted  solution  of 
nitric  acid,  composed  of  half  a  drachm  of  the  acid  in  an  ounce 
of  distilled  water.  This  for  a  bath  of  12  or  14  ounces  will,  in 
most  instances,  prove  sufficient.  An  efficient  method  of  making 
a  neutral  bath  is  to  dissolve  \\  oz.  of  crystals  of  nitrate  of 
silver  in  4  oz.  of  distilled  water,  and,  when  dissolved,  to  add  to 
it  4  grains  of  iodide  of  potassium  dissolved  in  a  drachm  of 
water;  shake,  and  add  16  oz.  of  distilled  water.  Now  add  to 
this  a  small  quantity  of  oxide  of  silver  (prepared  by  pouring 
a  solution  of  caustic  potash  into  a  solution  of  nitrate  of  silver, 
and  washing  well  the  precipitated  oxide)  until  the  solution, 
already  turbid  from  iodide  of  silver,  is  of  a  dirty  brown  colour. 
The  quantity  of  oxide  added  is  of  no  consequence.  When  the 
solution  is  filtered,  it  will  be  found  "very  slightly  alkaline,  in 
which  condition  it  would  yield  foggy  pictures.  Previous,  how- 
ever, to  using  it,  5  minims  of  the  following  diluted  acid  should 
be  added  : — . 

Nitric  acid  (1-50),       .  .  .  6  minims. 

Distilled  water,  .  .  .  i  ounce. 

The  bath  is  now  ready  for  use,  and  will  prove  to  be  in  the  most 
perfect  condition.  When,  from  repeated  use,  a  bath  becomes 
disordered,  and  produces  foggy  pictures,  it  should  be  tested  for 
acidity  by  immersing  in  it  a  slip  of  litmus  paper.  If  it  do  not 
turn  red  after  being  immersed  for  some  time,  add  some  of  the 
dilute  acid,  given  above,  until  it  do  so.  Fogging  in  an  old 
bath  is  easily  cured  by  rendering  it  slightly  alkaline  (with 
diluted  ammonia,  for  example),  and  exposing  to  sunlight  for 
some  time.      By  this  means  all  organic  matter  is  precipitated. 


PHOTOGRAPHY, 


After  filtration,  one  or  more  drops  of  the  diluted  nitric  acid  will 
be  found  necessary  to  restore  the  requisite  acidity.  Some 
baths,  which  from  use  or  abuse  have  failed  to  yield  clean  pic- 
tures, have  had  their  working  qualities  restored  by  adding  a 
few  drops  of  a  solution  of  cyanide  of  potassium,  which  in  the 
precipitation  of  the  cyanide  of  silver  formed  carries  down  the 
offending  organic  matter.  Each  photographer  seems  to  have 
his  own  favourite  method  of  restoring  the  bath  when  disorga- 
nised ;  but  as  the  restoration  occasionally  involves  a  loss  of 
time,  it  is  desirable  that  two  baths  be  kept  in  stock,  one 
relieving  the  other. 

Cheap  Collodion  Filter.  —  Procure  two  new  stoppered 
bottles,  wide-mouthed,  so  that  one  neck  will  fit,  after  grinding 
with  sand  and  water,  into  the  other,  inverted  ;  then  knock  out 
the  bottom  of  the  inverted  bottle,  and  grind  the  edges  ;  then 
fit  a  bung,  air-tight,  to  act  as  stopper;  cut  a  funnel-shaped 
cork  to  fit  in  the  neck  of  the  inverted  bottle,  and  run  a  quill  up 
one  side  of  the  cork  to  allow  the  air  to  pass  through  ;  cement 
it  tight  with  sealing-wax  inside  the  bottle  ;  put  your  cotton  wool 
into  the  bottle,  and  commence  to  filter,  which  will  answer  the 
same  as  those  sold  at  7s.  6d. 

Eurnt-in  Photographs. — Take  saturated  solution  of  bi- 
chromate of  ammonia,  5  parts  ;  albumen,  3  parts  ;  honey,  3 
parts  ;  and  dilute  with  20  parts  of  water.  Pour  this  over  a 
glass  or  enamelled  plate,  and,  after  drying,  expose  for  a  few 
seconds  under  a  glass  transparency.  Now  remove  to  a  damp 
room,  and  brush  over  the  surface  some  enamel  colour  until  the 
image  appear.  Fix  with  alcohol,  to  which  a  little  acetic  acid 
has  been  added,  and  when  dry  rinse  in  water,  dry  again,  and 
place  in  a  muffle  to  burn  in. 

Fixing  Prints. — In  various  scientific  journals  it  is  stated 
that,  if  toned  prints  be  placed  in  a  five  per  cent,  solution  of 
common  salt,  which  is  then  to  be  raised  to  the  boiling-point, 
and  left  ten  minutes,  they  will  be  perfectly  fixed,  and  merely 
require  washing.  A  very  careful  washing  is  necessar}^,  for  any 
trace  of  a  chloride  left  in  the  print  tends  to  destroy  it. 

Photography  on  Silk. — Immerse  the  silk  in  water,  i  oz.  ; 
gelatine,  5  grains  ;   chloride  of  sodium,  5  grains.      Hang  it  up 


212  PHOTOGRAPHY. 


to  dry ;  then  float  for  half  a  minute  on  a  fifty-grain  solution  of 
nitrate  of  silver ;  dry,  print,  tone,  and  fix  as  usual. 

Waterproof  Enamel  for  Card  Photographs. — The  follow- 
ing is  a  good  substitute  for  the  collodion  transfer  process,  and 
much  easier  of  application  : — First  apply  with  a  brush  to  the 
surface  of  the  card  a  solution  of  gum  arable,  of  sufficient 
strength  to  give  considerable  gloss  when  dry.  As  soon  as  dry, 
apply  a  coating  of  plain  collodion  as  in  coating  a  plate.  If  the 
collodion  is  not  very  tough,  two  or  three  coatings  may  be 
applied  to  advantage.  Finish  by  passing  the  card  through  a 
roller,  and  you  have  a  fine  gloss.  Take  care  not  to  have  the 
gum  solution  too  thick,  or  the  surface  will  crack  when  dry, 
though  there  is  but  little  danger  if  the  collodion  is  applied  soon 
after  the  gum  is  dry.  Gelatine,  instead  of  gum  arable,  will 
answer,  though  it  gives  hardly  as  much  gloss. 

To  Remove  Nitrate  of  Silver  Stains  from  the  Skin. — 

Cyanate  of  potassium  is  dangerous,  but  the  following  may  be 
safely  employed  : — Make  a  pretty  strong  mixture  of  solutions 
of  bichromate  of  potash  and  sulphuric  acid — say  two  parts 
saturated  solution  of  bichromate,  three  of  water,  or  one  of  sul- 
phuric acid.  Wash  the  hands  well  with  this,  then  rinse  them 
off,  and  have  at  hand  some  Lugol's  solution,  which  for  this 
purpose  may  be  made  as  follows  : — Iodide  of  potassium,  \  oz.; 
iodine,  40  or  50  grains  ;  water,  10  oz.  After  rinsing  off  the 
bichromate,  wash  the  stains  with  this  solution.  Under  its 
action  they  rapidly  lighten  in  colour  j  but  the  hands  become 
stained  deep  orange  colour  by  Lugol's  solution.  Finish  them 
with  some  negative  hyposulphite,  which  clears  off  all  the  colour 
that  remains. 

"Washing  Apparatus. — Attach  the  prints  to  a  surface  of 
perforated  or  woven  material  arranged  round  a  drum,  which 
revolves  in  a  trough  containing  water,  only  a  portion  of  the 
drum  being,  however,  submerged.  On  communicating  a  rapid 
motion  to  the  drum,  the  prints  are  alternately  immersed  in 
water,  and  then  whirled  round  with  sufficient  force  to  drive  off 
the  moisture,  thus  securing  an  effectual  application  to  the  alter- 
nate washing  and  draining  principle  which,  on  the  principle  of 
centrifugal  force,  is  recognised  as  desirable  in  getting  rid  of 
moisture. 


PHOTOGRAPHY.  213 


Cleaning  G-lass  Plates.  —  (i.)  Soak  them  in  a  solution 
made  by  dissolving  an  ounce  and  a  half  of  bichromate  of  potash 
in  a  pint  of  water,  and  adding  about  6  drachms  of  sulphuric 
acid.  Plates  soaked  in  this  solution  for  a  few  days,  and  then 
well  washed,  will  be  almost  as  good  as  new.  (2.)  Soak  them 
all  night  in  a  strong  solution  of  potash  and  water.  Then  place 
a  plate  on  a  flat  piece  of  washing  cloth,  and  with  a  tuft  of  the 
same  rub  each  side  and  the  edges  with  a  saturated  mixture  of 
common  salt  and  tripoli.  Set  the  plates  up  to  dry,  and  clean 
with  a  first  and  second  towel  kept  for  the  purpose,  or  wash  the 
plates,  adding  at  first  a  little  nitric  acid.  The  following  mix- 
ture on  a  cloth  and  tuft  of  its  own,  giving  a  final  rub  wherever 
the  fingers  have  touched,  is  recommended: — Old  collodion, 
I  oz.  ;  spirit  of  wine,  2  oz.  ;  water,  \  oz,  ;  tripoli,  i  oz.  ;  iodine, 
15  gi".  Shake  and  leave  on  plate  till  wanted.  (3.)  Make  a 
solution  of  nitric  acid,  i  part;  distilled  water,  3  parts.  Let 
the  plates  stand  in  this  for  three  days,  then  rub  them  well  with 
a  cork  while  wet,  and  swill  them  in  several  clean  waters. 

To  Clean  Silver  Plates. — Dr  C.  Calvert  gives  the  follow- 
ing as  a  good  plan : — Plunge  the  plate  for  half  an  hour  in  a 
solution  of  I  gallon  of  water,  i  lb.  hyposulphite  of  soda,  8 
oz.  muriate  of  ammonia,  4  oz.  liquid  ammonia,  and  4  oz. 
cyanide  of  potassium  ;  but  as  the  latter  substance  is  poisonous, 
it  can  be  dispensed  with  if  necessary.  The  plate  being  taken 
out  of  the  solution  is  washed,  and  rubbed  with  a  wash-leather. 
The  same  plan  may  be  adopted  for  all  kinds  of  silver  articles 
or  thickly-plated  table-ware. 

To  Copy  Cartes  withput  Eeduction  of  Size. — Place  the 
carte  or  other  object  to  be  copied  at  a  distance  from  the  lens 
of  twice  its  equivalent  focus,  the  sensitized  plate  being  placed 
at  an  equal  distance.  Thus,  if  the  lens  be  of  six  inches  equi- 
valent focus,  the  distance  between  the  picture  being  copied  and 
the  sensitive  plate  on  which  its  image  is  received  will  be  24 
inches,  the  lens  occupying  a  place  midway  between,  thus  having 
its  centre  1 2  inches  from  both  the  object  being  copied  and  the 
surface  on  which  it  is  copied. 

Double  Photographs. — These  may  be  taken  with  an  ordi- 
nary camera  in  the  following  way  : — Against  a  perfectly  black 
background,  take  a  photograph  of  the  person,  only  a  little  to 


214  PHOTOGRAPHY. 


one  side  of  the  plate.  After  it  has  had  the  proper  exposure, 
put  the  cap  on  the  lens,  but  do  not  shut  down  the  slide ;  then 
pose  the  person  again  according  to  taste — taking  care  that  his 
image  on  the  plate  shall  not  overlap  the  previous  image— and 
expose  again,  and  the  double  photograph  is  taken.  The  first 
picture  will  not  suffer  from  a  second  exposure  by  reason  of  the 
dark  background  being  a  negation  of  light.  To  insure  a  good 
picture  the  background  must  be  perfectly  black,  and  the  object 
well  illuminated.      An  acid  developer  is  preferable. 

New  Filtering  Apparatus. — An  economic  filter  and  per- 
colator has  been  devised  by  an  ingenious  combination  of  syphon 
tube  and  filtering  medium.  Any  test  liquid  may  be  drawn 
from  a  bottle  in  a  state  of  limpidity,  and  if  necessary,  returned 
again  turbid  to  the  stock  for  refiltration.  By  slight  modifica- 
tions the  apparatus  is  used  for  filtering  alcoholic  ethereal  or 
caustic  alkaline  solutions  out  of  contact  with  the  air,  and  it  can 
be  adapted  to  a  water-bath  so  as  to  admit  of  the  filtration  of 
gelatinous  liquids.  The  apparatus  is  specially  contrived  for 
use  amongst  photographers  ;  but  it  is  evident  that  there  are 
many  uses  in  chemical,  pharmaceutical,  and  manufacturing 
laboratories  to  which  this  apparatus  can  be  economically 
applied. 

Transferring  Photographs  to  Metals  for  Printing. — Mr 

Woodbury  of  Manchester  has  discovered  that  gelatine,  when 
dissolved  in  hot  water,  if  mixed  with  bichromate  of  potash  or 
ammonia,  dried  and  exposed  to  the  action  of  light,  be- 
comes insoluble — a  result  due  to  the  decomposition  of  the 
alkaline  bichromate  and  the  liberation  of  chromic  acid.  It  will 
be  seen  that  a  coat  of  the  bichromated  gelatine  on  a  glass  or 
metal  plate  placed  under  a  negative  and  exposed  to  light, 
would,  when  subjected  to  the  action  of  hot  water,  be  dissolved 
away  in  some  parts,  and  in  other  parts  unaffected,  thus  pro- 
ducing a  photographic  positive  in  relief.  Acting  on  these 
facts,  Mr  Woodbury  takes  the  image  in  relief  so  produced,  and 
either  by  mechanical  pressure  with  some  soft  metal,  such  as 
type  metal,  or  by  the  usual  process  of  electrotyping,  produces 
an  intaglio  impression  therefrom.  A  properly-prepared  ink, 
formed  with  gelatine  and  some  black  or  other  coloured  pigment, 
is  then  passed  over  the  plate,  with  which  the  impression  is 
filled  up  even  to  the  surface.     The  gradations  of  relief  in  the 


PHO  TO  GRAPHY.  2 1  ^ 


bichromatic  gelatine  print  form  gradations  of  depth  in  the  metal 
intaglio,  in  which  again  the  ink,  being  transparent,  forms  gra- 
dations of  blackness  proportioned  to  its  varying  thicknesses. 
A  modification  of  this  plan  is,  in  fact,  the  "  Woodbury  Pro- 
cess." 

■  The  Magnesium  Light. — In  reference  to  this  wonderful 
mode  of  illumination,  Professor  Schrotter,  of  the  Vienna  Aca- 
demy of  Sciences,  has  obtained  some  important  results,  of 
which  the  following  may  be  taken  as  an  epitome  : — The  mag- 
nesium light  promptly  and  powerfully  produces  fluorescent  as 
well  as  photographic  effects.  This  light  contains  an  extraordi- 
nary quantity  of  ultra-violet  rays,  the  spectrum  of  which  is  at 
least  six  times  as  long  as  that  of  the  luminous  portion.  Crys- 
tallized platino-cyanide  of  barium,  finely  powdered  or  made 
into  a  paste  with  gum,  so  that  it  can  be  fixed  on  paper,  gives 
a  powerful  fluorescence  when  exposed  to  this  light.  All  sub- 
stances which  become  luminous  by  isolation  acquire  this  pro- 
perty in  the  highest  degree  by  a  few  seconds'  exposure  to 
burning  magnesium,  whilst  with  the  sun  it  takes  five  to  ten 
minutes  to  produce  the  same  effect.  The  light  re-emitted  by 
these  bodies  has  no  photographic  power,  the  absorbed  chemical 
rays  being  degraded  to  purely  luminous  ones.  If  a  piece  of 
burning  magnesium  wire  is  brought  near  to  the  sides  of  a  white 
glass  cylinder,  filled  with  equal  parts  of  hydrogen  and  chlorine 
gases,  drops  of  hydrochloric  acid  will  be  seen  to  condense  on 
the  portion  of  the  cylinder  nearest  the  wire.  If  now  a  second 
piece  of  wire  is  burnt  on  the  opposite  side  of  the  glass,  an 
explosion  takes  place  almost  instantaneously.  By  means  of  the 
magnesium  light  instantaneous  photographs  may  be  taken. 

Artificial  Light  for  Photographers. — Professor  Falkland 
recommends  peroxide  of  nitrogen,  which  may  be  thus  pro- 
duced : — A  light  bottle  is  taken,  of  about  a  pint  capacity  ;  it 
is  fitted  with  a  cork,  through  which  passes  a  glass  tube,  bent 
to  a  right  angle  a  little  above  the  top,  and  the  end  drawn  out 
so  as  to  form  a  jet,  the  tube  being  bent  like  the  letter  U,  so 
that  the  jet  looks  upward.  The  only  other  essential  vessel  is 
a  test-tube,  or  narrow  beaker,  into  which  the  U  tube  can  easily 
dip.  Fragments  of  copper,  either  plate  or  wire,  are  placed  in 
the  bottle,  with  a  mixture  of  one  part  strong  nitric  acid  and  two 
of  water.     The  cork,  with  its  tube,  is  replaced  ;  the  little  beaker 


2i6  PHOTOGRAPHY. 

is  placed  in  a  vessel  of  warm  water,  and  the  bottle  is  placed  so 
that  the  bent  portion  of  the  tube  dips  into  the  beaker.  As  soon 
as  the  gas  comes  freely  through  the  jet,  some  bisulphide  of 
carbon  is  poured  into  the  beaker.  The  hot  water  with  which 
the  latter-  is  surrounded  quickly  vaporises  the  bisulphide, 
which,  when  set  fire  to,  burns  at  the  mouth  of  the  beaker  with 
its  usual  blue  lambent  flame  ;  but  from  the  gas  jet  upwards  for 
an  inch  or  more,  according  to  pressure,  arises  a  brilliant  cone 
of  flame,  giving  intense  light,  and  possessing  great  actinic 
power.  The  current  of  gas  should  be  tolerably  rapid,  and  the 
bisulphide  well  heated  to  ensure  the  best  effect,  and  it  should 
not  be  forgotten  that  the  burning  bisulphide  gives  off  abundance 
of  deleterious  fumes  of  sulphurous  acid. 

Easily-prepared  Photographic  Varnishes. — Procure  some 
good  gum  benzoin  ;  place  it  in  an  earthenware  or  metal  cap- 
sule, and  apply  moderate  heat  until  it  is  perfectly  fluid.  Then 
pour  it  upon  the  bottom  of  a  cold  plate,  and,  when  it  has  been 
quite  cold,  it  may  be  broken  off  in  pieces.  To  form  the  varnish, 
the  following  recipes  are  good.  The  second  is  more  expensive 
than  the  first,  but  a  little  better  : — 

(i.)  Dissolve  in  8  oz.  of  methylated  alcohol  i  oz.  of  the 
fused  benzoin  and  20  grains  of  sandarac  ;  then  add  20  drops 
of  mastic  varnish,  made  by  melting  gum  mastic,  and  adding 
turpentine  to  it  whilst  in  a  fluid  state.  The  impurities  will  soon 
settle,  and  the  varnish  is  ready  for  use. 


Fused  benzoin, 

1^  ounce. 

Sandarac, 

10  grains. 

Jalap  resin. 

\   ounce. 

Methylated  alcohol. 

8  fluid  ounces 

Mastic  varnish. 

20  drops. 

Should  either  of  these  varnishes  be  too  thick,  or  become  so  by 
use,  they  may  be  diluted  with  a  little  more  spirit.  Should  the 
spirit  be  too  strong,  which  may  be  known  by  its  partially  dis- 
solving the  collodion  film,  a  very  few  drops  of  water  may  be 
added.  When  using  either  of  the  above  preparations,  the 
negative  may  be  varnished  twice  without  any  danger.  This 
enables  us  to  touch  out  any  spots,  &c.,  on  the  negative,  and 
then  revarnish. 

(3.)   M.  Bussi  first  brushes  the  prints  over  with  a  solution  of 


PHOTOGRAPHY.  217 


gum  arable,  and  when  this  is  dry,  apphes  a  coating  of  collodion. 
The  following  are  the  proportions  recommended  : — i.  Clear 
transparent  gum  arable,  2  5  grammes ;  distilled  water,  1 00 
cubic  cents  ;  dissolve  and  strain.  2.  Gun  cotton,  3  grammes ; 
alcohol,  60  grammes ;  ether,  50  grammes.  By  this  double 
varnish  the  preservation  of  the  proofs  is  insured. 

Fixing  Solution. — A  good  fixing  solution  should  consist  of 
4  oz.  of  hyposulphite  of  soda  in  a  pint  of  water,  and  should 
always  be  used  fresh.  The  number  of  prints  of  a  given  size 
which  may  be  safely  fixed  in  a  definite  quantity  of  hypo-solution 
cannot  be  absolutely  stated.  Theoretically,  about  three  parts 
of  hyposulphite  of  soda  will  be  required  to  dissolve  one  of 
chloride  of  silver.  One  whole  sheet  of  sensitive  paper  has 
been  calculated  to  contain  about  from  25  to  30  grains  of 
chloride  of  silver.  On  this  theory  about  half  a  dozen  sheets  of 
paper  might  be  fixed  by  i  oz.  of  hyposulphite  of  soda.  In 
practice,  however,  so  many  other  circumstances  interfere,  that 
perhaps  not  more  than  one-fourth  of  that  number  ought  to  be 
fixed  in  the  quantity.  In  very  cold  weather,  the  solution  is 
comparatively  inactive  ;  it  is  well,  therefore,  to  raise  the  tem- 
perature to  about  60°  Fahr.  Thin  Saxe  paper  will  generally 
be  fixed  in  new  hypo,  of  the  strength  named,  in  about  ten 
minutes  ;  thick  Saxe  will  require  fifteen  minutes ;  thin  Rive 
paper  about  fifteen  minutes,  and  thick  Rive  about  twenty 
minutes.  A  slightly  albumenlzed  paper  will  be  fixed  more 
rapidly  than  a  highly  albumenlzed  sample ;  the  principle  being, 
that  the  more  horny  and  repellent  the  surface,  the  longer  the 
time  of  Immersion.  Complete  immersion  and  constantly  moving 
about  are  imperative. 

Focusing  Screen. — Take  a  piece  of  patent  plate-glass,  the 
size  required,  lay  it  down  on  a  perfectly  flat  bench  or  board, 
with  a  small  tin  tack  or  two  on  each  side  of  the  glass  to  keep 
it  in  place ;  then  take  a  pinch  of  the  Wellington  knife-powder, 
which  will  be  enough  to  grind  a  score  of  screens.  Apply  the 
powder  to  your  glass  with  a  few  drops  of  water,  and  mix  till 
about  as  thick  as  cream ;  then  take  a  piece  of  thick  plate-glass 
about  I  inch  square,  and  grind  the  surface  of  your  glass  with 
a  regular  motion  of  the  hand  slightly  bearing  on  till  you  get  a 
good  face,  which  will  take  from  half  an  hour  to  one  and  a  half 
hours  according  to  the  size  of  screen.    Apply  fresh  powder  and 


2 1 8  PHO  TO  GRA  PHY, 


water  at  timeSj  and  to  see  how  you  are  getting  on  with  it,  wash 
in  clean  water,  and  dry  very  steadily  before  a  fire  or  in  the 
sun  ;  and  if  the  screen  has  not  a  nice  regular  clean  face  apply 
the  same  means  over  and  over  again  if  required,  till  you  get 
it  to  your  mind,  but  do  not  put  on  any  fresh  powder  in  the 
finishing  for  the  last  quarter  of  an  hour,  as  it  will  give  a  finer 
surface. 

A  Good  Developer. — Mr  Carey  Lea  recommends  the  fol- 
lowing : — Dissolve  lo  grains  of  Nelson's  gelatine  in  an  ounce 
of  Beaufoy's  acetic  acid — that  at  lod.  per  lb.  Make  your  new 
developer  of  the  strength  you  are  accustomed  to  use,  of  course 
without  any  acid  ;  and  to  each  ounce  of  it  add  one  drachm  of 
the  gelatinised  acetic  acid.  You  will  be  pleased  with  the 
result,  and  with  its  cleanliness  and  ease  of  preparation.  This 
developer  will  be  found  to  bring  out  the  images  with  unusual 
vigour  and  brilliancy,  and  may  be  retained  on  the  plate  for  a 
long  time  without  "  fogging."  Where  from  unavoidable  diffi- 
culties under-exposure  has  arisen,  this  quality  alone  will  render 
it  invaluable. 

Sensitizing  Paper, — Albumen,  i  oz.  ;  water,  i  oz. ;  chloride 
of  ammonia,  i  o  grains.  The  paper  is  first  floated  on  this  and 
then  ironed.  It  is  then  again  floated  on  a  bath  of  nitrate  of 
silver,  of  the  strength  of  40  g  :.nsto  60  grains  to  an  ounce  of 
water. 

Purple  Staining. — Take  a  moderate-sized  cigar-box,  with 
lid  to  fit  close.  Half-way  up  the  box  bore  half  a  dozen  holes 
large  enough  to  admit  thread  each  side.  Strain  tightly,  from 
side  to  side,  a  half  dozen  pieces  of  thread  ;  fasten  with  wooden 
plugs.  After  the  prints  are  "  toned,"  "  washed,"  and  "  fixed" 
in  the  usual  way,  dry  them  well,  then  lay  them  faces  down  on 
the  thread.  Underneath  place  a  small  saucer  containing  some 
carbonate  of  ammonia.  Shut  the  lid  of  the  box  tightly.  Expose 
the  prints  to  the  fumes  from  five  to  ten  minutes,  or  longer  if 
required.  Examine  occasionally  until  the  desired  effect  is 
produced. 

Glass  Globes  for  Magnifying  Glasses. — A  small  piece  of 
very  fine  glass  sticking  to  the  wet  point  of  a  steel  needle 
is  to  be  applied  to  the  extreme  bluish  part  of  the  flame  of  a 
lamp;    (a  spirit  lamp  is  best;)  being  there  melted  and  run 


PHOTOGRAPHY. 


219 


into  a  little  round  drop,  it  is  to  be  removed,  upon  which  it 
instantly  ceases  to  be  fluid ;  folding  then  a  thin  plate  of  brass, 
and  making  very  small,  smooth  perforations,  so  as  not  to  leave 
any  roughness  on  the  surface,  fit  the  spherule  between  the 
plates  against  the  apertures.  The  same  may  be  inserted  in 
brass  or  ivory  tubes  for  the  photo-micro  objects. 

Freezing  Mixtures. — The  following  table  of  frigerific  mix- 
tures, without  ice,  may  be  useful  to  many  photographers  in  hot 
climates  or  our  own  country,  to  keep  cool  their  baths  or  other 
chemicals  by  immersing  their  bottles,  &c.  : — 


Mixtures. 

Thermometer  Sinks. 

Deg.  of  Cold 
produced. 

Common  salt 5  parts. 

Nitrate  potass 5      ,, 

Aqua 16      ,, 

From  +  50°  to  +  10° 

40 

Muriate  ammonia         .                 .     ?  parts 

From  +  50°  to  +  4° 

46 

Sulph.  soda 8      ,, 

Aqua 16      „ 

From  +  50°  to  +  4° 

46 

Aqua I      ,, 

Nitrate  ammonia i  part 

From  +  50°  to  —  7° 

57 

Carb.   soda i       „ 

Aqua I      )) 

Sulph.  soda 3  parts. 

From  +  50°  to  —  3° 

53 

From  +  50°  to  — 10° 

60 

Dilute  nit   acid 4 

Sulph.  soda 6  parts. 

From  +  50"  to  —  14° 

64 

Dilute  nit.  acid 4      m 

From  +  50°  to  —  12° 

62 

PhncnViatp  cnHa                    ...                   n  r>arts 

From  +  50°  to  — 21° 

71 

Dilute  nit.  acid 4      >. 

Sulph.  soda 8  parts. 

Muriaticacid 5      d 

From  +  50"  to  0° 

50 

Sulph.  soda 5  parts. 

Dilute  sulph.  acid 4      „ 

From  +  50°  to  +  3° 

47 

If  these  are  mixed  at  a  warm.er  temperature  than  that  expressed 
in  the  table,  the  effects  will  be  proportionately  greater ;  thus, 


220 


PHOTOGRAPHY. 


if  the  most  powerful  of  these  mixtures  be  made  when  the  air 
is  +  85°,  it  will  sink  the  thermometer  to  +  2°. 

Plate-Holder. — In  most  plate-holders  the  glass  is  fixed 
with  screws,   which  take  some  time  to  adjust.      In  this  little 

instrument    the    ad- 
^  cL^^s — K.^  justment   is    instan- 

taneous, besides  the 
advantage  of  more 
accurately  fitting  the 
edges  of  the  glass, 
and  thereby  lessen- 
ing the  chance  of 
breaking.  It  can 
also  be  used  as  a 
holder  for  exhibiting 
a  portrait  before  dry. 
It  is  easily  made,  and 
amateur  photograph- 
ers will  find  it  of 
service. 

H,    H,    handles; 
S,  S,  screws  allowing 
the  wood  W,  W,  to 
form  themselves  pa- 
rallel by  the  pressure  of  the  glass  edges  ;   H,  H,  holes  in  the 
lathe  ;   P,  pin  ;   F,  fixed  pin. 

Magic  Lantern  Photography. — Photographs  may  be  pro- 
duced with  a  camera  made  in  the  following  way  : — A  is  an 
ordinary   ;|-plate  lens,   B   the  focusing  screen,    C  a  slide  for 

holding  negative.  It 
will  be  observed  from 
this  sketch  that  trans- 
parencies may  be  pro- 
duced from  negatives 
of  the  same  size,  or 
larger  or  smaller. 
While  being  used  it  may  be  tilted  so  as  to  allow  the  light  of 
the  sky  to  pass  through  the  negative,  or  it  may  be  used  hori- 
zontally with  a  white  screen  to  reflect  light  through  the  negative. 
The  chemicals  are  the  same  as  are  used  for  negatives.     Care 


PHOTOGRAPHY. 


must  be  taken  that  the  silver  bath  and  developer  are  sufficiently 
supplied  with  acid  to  prevent  the  slightest  appearance  of  fog- 
ging. Or  you  may  print  from  the  negative  by  contact  on  glass 
or  mica  by  the  collodio-chloride  process,  which  gives  very  fine 
results. 

Black  for  Retouching  Photos. — Indian  ink  consists  of  the 
charcoal  of  fish  bones,  or  a  vegetable  substance,  mixed  with 
isinglass  size,  and  probably  honey  or  sugar  to  prevent  its 
cracking.  A  substance  much  of  the  same  nature,  and  appli- 
cable to  tinting  those  enlargements  denoted  black  and  white, 
may  be  made  thus  : — Take  3  oz.  of  isinglass,  form  it  into  a 
size  by  gentle  heat  in  double  its  weight  of  water ;  then  take 
half  an  ounce  of  Spanish  liquorice,  dissolve  it  also  in  double  its 
weight  of  water,  and  grind  it  up  with  half  an  ounce  of  fine 
ivory  black;  add  this  to  the  size  while  hot,  and  stir  well 
together  till  thoroughly  incorporated ;  finally  evaporate  away 
the  water,  and  cast  the  remaining  composition  into  leaden  or 
other  greased  moulds.  The  colour  of  this  composition  will  be 
equal  to  the  finest  Indian  ink  j  the  liquorice  will  render  it  easily 
dissolvable  on  rubbing  up,  and  prevent  its  cracking  or  peehng 
from  the  ground  on  which  it  is  laid. 

Eetouching. — Many  photographs  need  to  be  retouched. 
Retouching  is  undoubtedly  more  practised  on  the  Continent 
than  it  is  in  this  country,  and  is  occasionally  used  in  the  whole 
of  the  three  possible  forms  : — Retouching  on  the  model,  such 
as  strengthening  eyebrows,  deepening  eyelashes  with  coloured 
"  cosmetic,^'  or  the  use  of  violet  powder  to  red  hair  ;  retouching 
the  negative  with  pigment  or  blacklead  pencil ;  and  retouching 
the  print  with  a  suitable  water-colour.  The  darkening  of  eye- 
brows or  eyelashes  merely  for  securing  an  improved  effect  in 
the  portrait  is  of  course  unjustifiable,  inasmuch  as  it  would  alter 
nature  and  spoil  the  likeness,  unless  the  sitters  are  in  the  habit 
of  defacing  nature  by  appliances  of  powder,  paint,  and  dyes. 
The  use  of  violet  powder  to  modify  the  effect  of  red  hair  re- 
quires great  skill  not  to  produce  an  unnatural  effect,  but  it  is 
at  times  useful  and  effective.  Retouching  the  negative  requirse 
much  skill  to  produce  a  good  effect,  but  if  done  with  judgment 
and  skill  is  very  valuable.  It  is  effected  with  a  lead  pencil, 
to  soften  harsh  lines  in  the  face,  and  strengthen  the  detail  in  a 
few  shadows.      It  in  nowise  interferes  with  the  truth  of  nature. 


PHOTOGRAPHY. 


but  modifies  and  ameliorates  the  inherent  defects  of"  photo- 
graphy, or  of  the  photographic  negative.  In  retouching  a 
print,  the  great  aim  should  be  to  do  the  least  possible  to  effect 
the  end  in  view,  and  especially  to  let  the  addition  be  in  strict 
harmony  with  the  peculiar  characteristics  of  the  photograph. 
For  instance,  any  attempt  to  stipple  upon  a  faca  in  a  formal 
way  will  generally  issue  in  the  necessity  of  covering  the  whole 
face  with  such  stippling  or  hatching ;  whilst  a  few  skilful 
touches  imitating  the  quality  of  texture  or  kind  of  detail  in  the 
print  might  have  produced  a  really  better  and  more  pleasing 
result  with  one-tenth  of  the  labour. 

Composition  Pictures. — In  the  Exhibition  of  1871,  many 
photographs  that  were  much  admired  were,  in  fact,  simply 
"  compositions  '^  from  several  negatives.  Composition  pictures 
— says  Mr  E.  Dunmore,  the  well-known  amateur  photographer 
— are  certainly  the  most  daring  attempts  to  burst  the  bounds 
of  what  is  considered  the  limits  of  a  process,  and  are  attempts 
worthy  of  imitation  by  all.  Light  and  shadow  are  our  sheet 
anchors.  A  clever  arrangement  of  the  chiaroscuro,  and  a  few 
touches,  will  make  a  picture,  when  myriads  of  touches  and  bad 
lighting  will  make  a  photograph  the  derision  of  every  one  who 
knows  anything  about  art,  perfect,  perhaps,  in  its  chemical 
aspect,  but  horrible  in  its  pictorial  one.  When  we  see  a  beau- 
tiful result,  we  are  apt  to  overlook  the  time,  care,  skill,  energy, 
and  battling  with  almost  insuperable  difficulties  necessary  to  its 
production..  The  result  is  all  we  know,  if  it  be  good  or  bad. 
If  good,  no  one  can  imitate  it  without  undergoing  the  same 
ordeal  to  procure  the  negatives. 

Reproducing  Negatives. — When  it  is  desired  to  duphcate 
a  negative,  the  following  plan  is  to  be  adopted  : — Spread  on  a 
glass  the  same  size  as  the  negative  a  mixture  of  bichromate 
solution,  gum,  and  honey,  to  expose  under  the  negative,  and, 
after  exposure,  dust  over  with  a  f)igment,  which  adheres  to  the 
unexposed  parts,  and  forms  a  negative.  This  is  to  be  washed 
with  a  mixture  of  alcohol  and  glacial  acetic  acid,  which  removes 
the  bichromate  without  dissolving  off  the  gum.  Negatives 
obtained  in  this  way  are  reversed,  and  give  reversed  positives. 
They  are  useful  for  photolithographic  transfers.  Instead  of 
dusting  the  exposed  plate  with  pigment,  enamel  powder  may 
be  used,  and  the  plate  may  then  be  burned  in,  and  a  negative 


PHOTOGRAPHY.  223 


of  absolute  permanence  be  obtained.  (It  seems  doubtful  if 
such  a  burned-in  negative  could  have  the  fulness  of  detail  of  a 
collodion  negative,  from  the  tendency  of  colours  to  run  a  little 
when  fused.) 

To  Photograph  Drawings,  Manuscripts,  &c. — The  usual 
method  is  to  copy  them  by  reflected  light,  but  Professor  Fowler 
adopts  the  following  : — The  paper  suitable  is  very  thin,  homo- 
geneous in  texture,  and  machine-ruled  or  lined  in  the  pulp  or 
mass  of  the  paper  itself.  Upon  these  lines  the  manuscript  is 
carefully  and  boldly  written,  and  so  that  not  a  single  stroke  is 
wanting.  As  soon  as  the  page  is  complete,  and  the  ink  quite 
dry,  make  the  paper  transparent  with  a  mixture  of  olive 
oil  and  turpentine,  applied  by  means  of  a  fine  sponge  to  the 
back.  The  sheets  are  then  hung  up  to  dry.  To  obtain  a 
negative  of  the  manuscript,  use  dry  tannin  plates,  and  print  by 
contact.  In  the  printing-frame  place  first  a  clean  flat  glass  ; 
upon  this  lay  the  manuscript,  the  back  in  contact  with  the 
glass  ;  and,  last  of  all,  press  the  tannin  plate  into  close  apposi- 
tion with  the  writing  of  the  manuscript.  The  door  is  then 
closed.  This  operation  is  performed,  of  course,  in  the  dark 
room.  The  front  of  the  printing-frame  is  covered  with  a  thin 
board,  slate,  or  tin  plate  ;  and  having  brought  it  in  this  condi- 
tion into  the  light,  the  board  is  removed  from  the  front,  and  the 
manuscript  is  exposed  for  a  few  seconds.  Replace  the  board, 
and  carry  the  printing-frame  back  into  the  dark  room.  Here 
the  negative  is  developed  with  pyrogallic  acid  and  silver,  and 
then  fixed.  The  parts  beneath  the  ink-marks  are  naturally 
transparent,  whilst  all  the  rest  is  uniformly  opaque  to  the  rays 
of  light.  This  opacity  is  much  more  dense  and  uniform  than 
that  which  is  obtained  by  copying  by  means  of  reflected  light. 
After  washing,  the  plate  is  dried  and  varnished.  A  dozen 
similar  negatives  are  soon  taken  in  this  way  ;  and  it  is  then  an 
easy  task  to  print  several  hundred  facsimile  copies  of  the  manu- 
script or  drawing. 

Photographic  Prints  on  Linen  and  Cotton. — Handker- 
chiefs, &c.,  are  often  ornamented  with  photographs,  and,  as  a 
matter  of  curiosity,  it  may  be  as  well  to  describe  the  process. 
The  linen  or  cotton  cloth  is  first  freed  from  its  '*  dressing,"  and 
then  coated  with  the  following  preparation  : — Distilled  water, 
125  cubic  centimetres;  chloride  of  ammonium,  i  gramme;  the 


224 


PHOTOGRAPHY. 


white  of  one  ^gg.  The  surface  of  the  fabric  is  allowed  to 
remain  for  five  minutes  in  contact  with  the  albumen  mixture, 
then  dried,  and  afterwards  rendered  sensitive  by  floating  it  on 
a  ten  per  cent,  solution  of  nitrate  of  silver.  The  latter  opera- 
tion takes  five  or  six  minutes,  and  requires  to  be  conducted 
with  great  care,  as  spots  will  inevitably  occur  in  places  where 
the  silver  solution  touches  an  unalbumenized  portion  of  the 
fabric.  The  printing  should  take  place  on  the  same  day  as  the 
sensitizing,  the  remaining  operations  being  proceeded  with  in 
the  ordinary  manner.  Photographs  produced  by  this  method 
are  very  permanent,  and  may  be  washed  with  soap  without 
sustaining  injury. 

Design  for  a  Photographic  Studio. — Here  we  have  the 
ground-plan  of  a  photographic  studio  which  has  been  found  very 
effective.  It  is  of  what  has  been  called  the  tunnel  class,  but 
differs  from  the  kind  recommended  in  the  photographic  journals 
in  the  larger  amount  of  light  it  admits.      Indeed  it  is  probable 


-7-^0 -x-^ 


>Mie 


that,  in  an  open  situation,  too  much  light  would  find  its  way 
to  the  sitter,  and  some  would  therefore  have  to  be  shut  off; 
but  of  two  evils,  too  much  and  too  little  light,  the  former  is 
certainly  the  smaller,  and  is  moreover  advantageous,  inasmuch 
as  when  decreased  the  shut- out  portion  serves  as  a  kind  of 
reserve  force  for  dull  weather.  It  is  based  upon  a  design  of 
admitted  excellence,  but  the  proportions  differ  considerably,  so 
as  to  fit  it  for  the  use  of  amateur  photographers. 


PHOTOGRAPHY. 


225 


Dark  Box  for  Field-work. — When  set  up  for  work,  the 
dimensions  of  the  box  herewith  described  are  : — Length,  18  in.; 
width,  14  in.  ;  height,  13  in.  ;  outside  measure  when  packed, 
5!  in.  thick,  or  about  the  size  of  a  soldier's  knapsack.  It  is 
made  of  very  thin 
deal  covered  with 
oil-cloth,  and  has 
round  each  corner 
pieces  of  sheet- 
copper  riveted. 
At  each  corner, 
also,  inside,  there 
is  a  light  ash  up- 
right, hinged  by 
passing  a  screw 
through  the  long- 
est side  of  the  box, 
and  riveting  it  in 
the  upright,  which 
can  then  fold  down 
between  the  edges 
of  the  sides,  top 
and  bottom.  There 
are  three  thick- 
nesses of  black 
calico  tacked,  and 
in  the  top  of  the 
box  there  is  a  lid 
of  sufficient  size 
through  which  the 
bottles  of  chemi- 
cals, &c.,  are 
handed.  To  set 
up  the  box  for 
working  it  is  fas- 
tened on  its  tripod 
stand,  the  screw- 
bolt  of  which,  by 
a  simple  contrivance,  slips  into  a  groove  in  the  box,  and  the 
straps  which  go  quite  round  being  undone,  the  lid  is  raised  ; 
and  the  top  being  supported  with  one  hand,  the  uprights  are 


226 


PHOTOGRAPHY. 


lifted  with  the  other,  and  entering  into  small  blocks  in  the  top, 
stretch  the  calico  sides,  and  the  whole  thing  is  quite  firm.  In 
the  side  of  the  calico,  next  the  operator,  there  are  sleeves 
through  which  he  passes  his  hands  to  enable  him  to  see  what 
he  is  about.  There  is  a  large  plate  of  yellow  glass  in  the  lid, 
and  when  his  eyes  are  shaded  he  can  see  perfectly.  The  shade 
is  made  of  stiff  oil-cloth  covered  with  black  velvet ;  it  has 
pieces  of  sheet-iron  riveted  on  to  it  at  right  angles,  which  slip 
into  grooves  in  the  hd.  Anything  to  cover  the  head  would  do 
as  well,  but  the  other  plan  is  the  most  convenient  to  admit 
light  into  the  box.  There  is  a  yellow-glass  window  in  the  side 
farthest  from  the  operator,  made  by  glueing  a  light  wooden 
frame  to  the  calico,  the  glass  resting  in  a  rabbet,  and  having  a 

metal  frame  screwed  over 
it.  There  is  another 
small  light  in  the  lid 
which  can  be  shut  out  by 
a  revolving  metal  cover 
from  the  inside  ;  but  it 
is  only  needed  in  a  very 
dull  light.  In  the  floor 
of  the  box  there  is  a 
yellow  glass,  so  that  in 
developing  it  can  be  seen 
when  all  the  half  tones 
are  out  by  looking  through 
the  negative,  a  point  of 
great  importance.  The 
bath  is  sunk  through  an 
opening  in  a  bag,  also  the  dark  slide  when  done  with.  These 
bags  have  strong  wire  frames  at  top  to  prevent  their  sHpping 
through  the  openings.  Keep  the  bath  always  covered.  The 
holes  in  the  floor  of  the  box  have  sheet-iron  frames  riveted 
over  them  to  support  the  wood.  The  water-can  is  placed  on 
the  top,  and  the  water  is  conducted  on  to  the  plate  by  an 
elastic  tube,  a  patent  shp  cutting  off  the  stream.  The  waste 
water  from  the  dish  is  carried  off  by  a  tube  passing  through  the 
bag  in  which  the  bath  is  placed.  There  is  a  wooden  rack  for 
bottles  which  contains  everything  for  a  long  day's  work,  includ- 
ing chemicals  for  extra  developing  and  fixing  solutions,  and 
bottle  of  bath  solution  for  filling  up  ;  the  gutta  percha  or  glass 


PHOTOGRAPHY. 


227 


bath  is  made  water-tight  by  a  strap  of  wide  hoop-iron  passing 
under  it,  and  the  ends  being  turned  up  the  clamp  catches  them 
and  presses  the  piece  of  wood  and  the  indiarubber  down  on  the 
top  of  the  bath.  When  the  box  is  packed  for  travelhng,  the 
bath  Hes  inside  the  tin  water-tray  or  dish  ;  and  it  rests  on  the 
dark  shde.  The  bottle-rack  and  the  water-can  fill  up  the  re- 
maining space  ;  the  cleaning  cloths  keeping  all  snug.  The 
plate-box  hooks  oh  the  lid,  protecting  the  yellow  glass  ;  it  will 
hold  six  plates,  either  half  plates  (6^  x  4|),  or  4  x  5  plates  ; 
they  rest  at  two  corners  in  grooves,  and  at  the  other  corners 
on  movable  slips  of  wood,  so  that  both  sizes  can  be  carried 
together,  and  cannot  possibly  get  rubbed  ;  of  course  the  smaller 
plates  must  be  the  upper  ones.  The  folding  tripod-stand  is 
fastened  to  the  top  above  the  plate-box.  Carry  the  pack  like  a 
knapsack,  and  you  can  go  six 
or  eight  miles  without  fatigue  ;  A 

the  weight  is  onlv  about  20  lbs. 


Dark  Tent. — Mr  Wilson,  of 
Aberdeen,  recommends  the  fol- 
lowing plan  :  —  The  tent  is 
composed  of  a  light  tripod  of  the 

usual  height  for  the  framework,  and  a  covering  of  three  folds 
of  twilled  calico,  two  black  and  one  yellow.  The  cloth  is  first 
cut  into  lengths,  about  a  foot  more  than  the  length  of  the  tripod 
frame,then  folded  from  B 

opposite  corners,  so 
that  each  piece  may 
be  cut  along  the  dia- 
gonal of  the  parallelo- 
gram into  two  triangles 
A,    which    are    after- 

wards   sewn   together     '  ^^  \  \  \  /  /  /     .-^  1 

so  as  to  form,  when 
laid  flat  on  the  floor, 
about  three  -  quarters 
of  a  circle  B.  The 
edges  are  cut  evenly 
round,  and  bound  with  tape,  and  when  a  square  hole  has  been 
cut  out  of  the  two  outer  folds  of  black  calico  and  two  folds  of 
yellow  cotton  to  act  as  a  window  have  been  substituted,  the  tent 


228 


MUSICAL  INSTRUMENTS. 


is  complete.  It  can  be  pitched  in  half  a  minute  by  stretching  out 
the  tripod,  until  the  legs  are  about  three  feet  apart ;  and  when 
a  few  stones,  pieces  of  wood,  or  anything  handy,  are  placed 
round  the  bottom  inside,  it  is  ready  for  the  bath  and  bottles. 


Portable  Photographic  Tent. — The  roof  is  made  of  four 
pieces  of  timber  4  feet  long  and  about  f  in.  square,  which  are 
hinged  to  a  circular  piece  of  wood  about  4' in.  in  diameter,  in 
such  a  way  as  to  admit  of  their  shutting  up  like  an  umbrella. 
To  each  of  these  "rafters"  is  nailed  double  calico,  black  lined 
with  yellow.  The  eave  overhangs  about  3  in.,  on  the  inside  of 
which  are  stitched  strong  hooks  about  6  in.  asunder,  on  which 
are  hung  the  sides  or  walls  of  the  tent.  The  legs  are  the  same 
size  as  the  rafters,  4  feet  long  and  |-  in.  square.  They  are 
hinged  to  the  inside  of  the  rafters,  and  can  fold  in  when  shut 
up.  Each  leg  is  connected  by  a  strong  galvanized  wire  which 
hooks  into  eyes  (those  used  for  stair  rods  will  answer)  close 
under  the  eave.  Four  strong  cords  from  the  top  pass  down 
each  angle,  through  a  couple  of  eyes,  on  to  the  ground,  where 
they  are  secured  by  iron  pins,  thus  making  the  whole  perfectly 
steady.  The  sides  are  also  black  lined  with  yellow,  and  for 
convenience  are  divided  into  two  parts  4  feet  3  in.  wide,  and  long 
enough  to  allow  an  overlap  of  i  foot  at  each  joining.  The 
P,(H  I  door  is  made  by  un- 

hooking three  or  four 
eyes,  folding  back 
the  curtain,  and 
hooking  it  on  some 
of  the  inside  hooks. 
Thus  a  perfect  pho- 
tographic tent  is 
made,  which  might 
be  serviceable  for 
several  other  pur- 
poses. 

.ffiolian  Harp.— 

In  the  first  place,  a 
box  must  be  made 

of  twelve-cut  board  ;  the  length  to  be  the  width  of  the  window; 

the  box  6  in.  deep,  and  from  8  in.  to  12  in.  in  width  as  shown 


MUSICAL  INSTRUMENTS. 


229 


fig.  I.  A  board  must  next  be  cut  to  fit  the  top  of  the  box,  with 
two  openings  A  for  sound,  and  be  glued  down.  Take  two 
pieces,  as  B,  and  glue  across,  as  shown  in  C ;  these  are  to  act 
as  bridges  for  the  strings. 

The  strings  are  next  to  be  placed  across  from  one  end  to  the 
other,  passing  over  the  top  of  the  sounding-board,  and  resting 
on  the  two  bridges  ;  the  strings  must  be  fastened  by  placing 
nails  at  one  end  to  attach  them,  and  screws  at  the  other,  the 
screws  to  be  used 
so  as  to  slacken 
and  tighten  as  re- 
quired. Over  these 
strings  must  be 
placed  another 
piece,  as  A,  with- 
out the  incisions  ; 
this  is  to  rest  on 
four  small  pegs,  3 
in.  in  length,  placed 
at  each  corner. 
The  window  is  then 
to  be  shut  down 
on  the  top  of  this 
board,  as  in  fig.  2, 
when  the  wind  will 
pass  through  the 
strings,  causing  a 
most  delightful 
harmony,  especi- 
ally if  a  door  or 
window  in  an  op- 
posite part  of  the 
apartment  be  left 
open  to  cause  an 
extra    draught    or 

current  of  air.  The  strings  must  be  of  small  catgut,  and  must 
not  be  made  too  tight,  or  they  may  be  stretched  simply  between 
two  thin  boards,  about  i  in.  or  \\  in.  apart,  and  made  to  fit 
the  window. 

Another   method. — The   annexed   sketches  will   explain  : — • 
I.   Top,  2  ft.  6  in.  long.    5   in.  wade,  ^  in.   thick,      2,   Bottom, 


230 


MUSICAL  INSTRUMENTS. 


the  same  length,  &c.,  as  top,  with  two  bits  of  wood  aa,  2  in. 
by  5  in.  long,  \  in.  thick  at  each  end,  bb  two  bridges  for  the 
strings  to  rest  on.  The  strings  must  not  be  tightened  too 
much,  but  be  regulated  so  as  to  be  moved  by  the  wind  ;  cc  four 
screws  to  hold  the  box  firm.  The  strings  must  be  in  the  centre 
of  the  opening  0.     You  must  obtain  four  catgut  strings,  two  of 

the    smallest    size, 
F«C.k  to  put  in  the  front 

side,  that  is  the 
side  which  the  wind 
first  acts  on,  and 
the  other  two  at 
the  back.  The  four 
strings  are  fastened 
to  the  four  holes  at 
each  end,  as  seen 
in  fig.  2,  and  the 
top  must  be  plain, 
with  two  holes  at 
each  end  to  screw  to  the  bottom.  When  you  wish  to  hear  it 
play,  fix  it  under  the  bottom  sash  of  the  window,  taking  care 
to  put  two  pegs  in  the  top  to  keep  it  from  falling.  One  made 
on  the  above  plan  played  for  six  or  seven  years. 


FlC. 2.  THE  BOTTOM 

u 
-Z  n  R- 


^S 

- 

0^                                        ..        . 

ZT  " 

O-l 

2     _ 

H  a 

^L- 

; 

I!  0 

-z/e- 


Home-made  Violins. — The  more   simple  the  form  of  the 
instrument  the  better  will  be  the  tone.      The  backs  and  sides 

of    the     Cremona 

A 


violins  were  made 
of  maple,  and  the 
bellies  of  pine  wood 
well  seasoned  and 
dry.  A  plain  deal 
box,  with  a  violin 
neck  glued  to  one 
of  its  ends,  and  fitted  up  with  strings,  bridge,  &c.,  will  be  found 
far  superior  in  point  of  tone  to  the  ordinary  run  of  violins.  The 
back  and  belly  are  of  soft  pine  wood  (the  grain  very  strong  and 
equidistant)  14  in.  in  length  ;  width  at  bottom  end  8|-  in.  ; 
width  at  top  end  6  in.  Of  course  the  back  and  belly  are  made 
of  two  parts  each,  glued  straight  up  the  middle,  and  the  thick- 
ness of  each  is  i-5th  of  an  inch  in  the  middle  (where  the  pieces 


MUSICAL  INSTRUMENTS. 


are  joined  together),  diminishing  gradually  right  and  left  to 
I- 1 2th  of  an  inch  at  the  edges  ;  the  depth  of  sides  is  2  in.,  and 
the  sound-holes  are  straight  instead  of  being  curved  like  an  f. 
The  neck  and  pegs  are  the  same  as  other  violins.  If  the 
instrument  is  to  be  varnished,  the  best  varnish  is  shellac,  dis- 
solved in  spirits  of  wine.  Any  druggist  will  give  it  the  proper 
stain.  It  does  not  signify  what  the  colour  is.  The  wood  must 
not  be  stained  before  varnishing,  as  it  will  close  up  the  pores, 
and  so  prevent  a  free  and  energetic  vibration.  The  prefixed  is 
a  rough  sketch  of  the  home-made  viohn  ;  the  dotted  lines  show 
the  blocks  in  the  inside  for  strengthening  the  instrument.  Its 
internal  capacity  is  greater  than  ordinary  violins.  The  young 
musician,  who  wants  an  eloquent  violin  of  the  ordinary  shape, 
will  find  full  directions  for  striking  out  and  making  entirely  in 
Otto's  "  Treatise  on  the  Violin," 

The  tone  of  a  violin  depends  chiefly  upon  the  form,  size, 
thickness,  and  quality  of  the  wood.  The  size  of  the  body  of  a 
violin  is  about  14  in.  long,  4|  in.  wide  across  the  "waist,"  or 
narrowest,  and  8^  in.  over  the  widest  part  of  the  back  and 
belly.  If  the  length,  14  in.,  be  divided  into  72  parts,  it  will 
form  a  convenient  scale  for  measurement,  and  will  accordingly 
be  so  made  use  of  in  this  short  account. 

The  form,  taking  the  violin  as  seen  flatways,  is  best  obtained 
from  some  violin  of  good  pattern.  But  as  power  and  brilliancy 
of  tone  are,  in  a  great  degree,  due  to  the  reflection  of  the  vibra- 
tions (passing  from  the  bow  down  the  bridge  and  sound-post 
into  the  body  of  the  violin),  from  the  ribs  as  the  containing 
boundary,  back  to  the  centre  of  the  body  (a  fact  not  noticed 
by  Otto  or  others),  the  form  of  the  sides  or  ribs  is  a  matter  of 
some  consequence.  That  a  square  violin  reflects  these  vibra- 
tions only  from  side  to  side  and  end  to  end,  and  does  not  con- 
centrate, or  focus  them  anywhere,  must  be  obvious.  And  that 
such  a  form  has  power,  is  due  only  to  its  greater  capacity,  it 
being  well  known  that  large  violins  are  most  powerful  in  tone, 
and,  therefore,  in  most  request  with  skilled  concert-players. 
As  to  the  form  taken,  as  the  violin  is  seen  sideways,  it  should 
be  even  more  particularly  adapted  for  the  reflection  of  vibrations 
noticed,  and  is  evidently  so  in  all  good  instruments.  The 
section  of  the  back  and  belly  of  these,  taken  at  the  narrowest 
part  or  waist,  will  be  found  (outwards)  concave  near  the  side 
and  convex  in  the  centre,  and  this  plan  prevails  more  or  less 


232 


MUSIC  A  L  INSTR  UMENTS. 


all  round  the  body.  Old  violins  are,  however,  constantly  seen 
with  a  wholly  different  model,  convex  in  almost  every  part, 
high,  and  bulging  towards  the  ribs  ;  but  they  have  always  a 
dull,  hollow,  tubby  sound,  which  appears  as  if  it  could  not  get 
out,  owing,  doubtless,  to  the  form  inclining  the  reflection  of 
vibration  towards  the  ribs,  instead  of  to  the  centre  of  the  body. 
It  would  be  difficult  to  give  an  exact  section  of  back  or  belly 
of  a  violin,  as  it  must  depend  upon  the  eye  (bearing  in  mind 
the  principle  of  reflection  of  sound)  to  model  out  these  curved 
forms  into  flowing  gradations  from  concave  to  convex. 

One  mistake  into  which  a  beginner  is  likely  to  fall  may  here 
be  pointed  out.  As  the  edges  of  the  back  and  belly  are  a  trifle 
thicker  where  they  are  glued  to  the  sides,  and  as  the  outside  is 

formed  before  hol- 
lowingoutthe  inner, 
allowance  must  be 
made  for  this  extra 
thickness,  or  the 
inner  side  of  the 
back  or  belly  will 
be  concave  where  it 
should  be  convex, 
as  at  A,  the  proper 
form  being  as  at  B. 
Violin-making  is 
an  art  requiring  ex- 
perience and  skill,  and  those  wishing  to  succeed  should,  as  in 
other  arts,  study  what  has  been  done  by  the  most  skilful ;  and 
in  this  department  Straduarius  and  Joseph  Guanerius  stand 
foremost,  and  have  left  the  finest  specimens  of  their  particular 
skill,  which  should  form  the  model  for  a  good-toned  violin. 


Rffl 


Dimensions  of  various  paints  of  Violin. 
Sides  or  ribs,     ^  of  a  part  thick. 
Sides  or  ribs^  6^  parts  wide,   diminishing  gradually  to  6  parts 

at  the  neck. 
Side  linings,         \  part  thick,    ij  parts  broad. 
Upper  block,  lo    parts  broad,  4  thick. 
Lower      „         8        „  „       4     „ 

Corner     „  8        „    „       4     „ 

Belly  under  the  bridge  two-thirds  of  a  part  thick,  diminishing 


MUSICAL  INSTRUMENTS. 


233 


gradually  to  one-third  at  the  edges.  Back  under  the  bridge 
one  part  thick,  diminishing  to  half  a  part  at  the  edges.  The 
external  edges  of  back  and  belly  should  be  left  rather  thicker 
for  strength.  Bass  bar,  an  inside  piece  glued  to  the  belly  and 
standing  under  and  supporting  the  left  foot  of  the  bridge, 
thirty-six  parts  long,  one  and  one-fifth  parts  broad,  two  parts 
thick  in  the  centre,  diminishing  to  two-thirds  of  a  part  at  each 
end.      In  fig.  i,  a  half  section,  these  parts  are  shown. 

Wood. — In  good  violins  the  back,  ribs,  and  neck,  with  key- 
box,  are  made  of  a  species  of  foreign  sycamore  or  maple,  called 
harewood,  the  belly  and  sound-post  of  Swiss  deal  :  for  the 
former,  English  sycamore  is  too  soft ;  maple  would  probably 
be  the  best  English  wood  ;  and  the  best  substitute  for  Swiss 
would  be  Finland  deal,  selected  free  from  turpentine,  light  in 
weight,  and  of  fine  and  regular  bate  or  grain,  from  a  centre 
plank,  which  should  show  the  grain  on  the  edge  as  well  as  the 
surface.  All  wood  used  should  be  thoroughly  seasoned.  It  is 
said  that  wood,  if  often  baked  for  the  purpose  of  more  completely 
freeing  it  from  turpentine,  &c.,  a  certain  crispness  in  the  tone 
may  be  thus  acquired.  It  should  have  been  stated  that  the 
small  blocks  are  made  of  sallow,  but  deal  may  be  used. 


Tools. — In  making  this  violin,  it  is  necessary  to  have  20  or 
more  small  wooden  cramps  made  of  close-grained  wood,  like 
the  sketch  ;  of  beech 
or  birch,  3  inches  or 
more  in  length,  i  in. 
wide  at  each  end, 
and  half  an  inch 
thick,  with  a  notch 
dd  \\  in.  long,  to 
receive  the  edge  of 
the  violin,  which  we 

get  tight  by  two  thin  wedges,  i^-  in.  long,  |-  in.  broad,  and  | 
in.  thick,  entering  one  at  each  side,  as  at  c,  the  wedges  being 
placed  on  the  back  and  belly,  but  not  on  the  ribs.  If  in  the 
event  of  being  often  wanted,  wire-tapped  screws  wormed  into 
the  ends  of  the  cramps  as  shown  might  be  used  made  of  about 
No.  10,  or  i-ioth  of  an  inch  wire,  and  got  tight  against 
wooden  hooks,  as  at  c,  b  being  the  violin.  In  commencing, 
let  the  amateur  first  cramp  the  back  to  the  sides,  exactly  where 


234  TAXIDERMY. 


it  requires  to  be,  with  five  or  six  cramps  on  each  side ;  then 
release  one  side,  which  will  spring  off  suifificiently  to  be  glued. 
When  glued,  nip  close  together  with  ten  or  twelve  cramps. 
This  done,  release  the  other  side,  glue  and  cramp  it  in  the 
same  manner.  Then  set  it  to  dry  and  harden  for  a  day  or  two 
before  repeating  the  same  process  with  nothing  on  the  belly. 
When  thoroughly  dry,  scrape  off  any  superfluous  glue  from  the 
edges.  If  any  crevices  appear,  trace  a  little  hot  thinish  glue, 
with  the  small  end  of  a  skewer,  round  the  edges,  so  as  to 
smooth  or  fill  up  every  crevice. 

Musical  Vibration. — The  tones  of  violins  being  so  various, 
it  is  almost  difficult  to  judge  the  difference,  or  best,  from  the 
various  tastes  of  players.  Some  like  a  fine  or  firm  tone,  some 
a  loud  tone,  some  a  hard,  sharp,  or  leading  tone,  some  a  crisp 
or  wiry  tone.  Each  may  be  deemed  best  in  the  estimation  of 
such  a  variety  of  advocates.  A  violin  with  back,  belly,  and 
sides,  all  of  pine,  is  not  likely,  as  a  general  rule,  to  produce  a 
fine  clear  tone,  save  from  the  spontaneous  harmonizing  vibra- 
tions, perchance,  of  back  and  belly.  It  is  impossible  for  any 
manufacturer  of  violins,  however  defined  his  rule  for  construc- 
tion may  be,  to  produce  two  or  more  consecutive  violins  that 
will  possess  an  equal  number  of  free  vibrations  of  back  and 
belly  (minus  the  sounding-post),  that  is  to  say,  the  backs  and 
bellies  of  each  violin  would  not  be  in  union  with  each  other  in 
their  vibrations  ;  nor  equal  in  power,  tone,  or  quality.  No 
doubt,  the  finest-toned  violins  would  be  those  whose  natural 
free  vibrations  of  backs  and  bellies  are  in  unison,  or  in  octaves 
to  each  other.  But  such  occurring  by  chance  is  a  mere  lottery. 
Even  those  whose  spontaneous  free  vibrations  closely  harmo- 
nise together  will  have  an  especial  superiority  over  others 
whose  free  vibrations  class  amongst  the  wide-spread  intervals 
of  discord. 

Preserving  Skins. — Small  skins  may  be  preserved  in  the 
following  manner.  They  are  first  cleaned  and  scraped  ;  they 
are  then  rubbed  over  with  arsenical  soap,  prepared  thus  : — To 
four  pounds  of  white  curd  soap  add  one  pound  of  arsenic  and 
one  ounce  of  camphor  ;  cut  the  soap  into  thin  slices,  and  dis- 
solve it  in  one  pint  of  water.  When  melted,  add  the  arsenic 
and  camphor,  stirring  them  well  together,  and  boil  again,  until 
the  substance  of  a  thick  paste  is  attained,  and  pour  it  into  jars 


TAXIDERMY.  235 


while  hot.      When  cold,  tie  it  up  carefully  with  bladder,  and  it 
will  retain  its  qualities  for  years. 

Rabbit  skins,  and  indeed  any  moderately  small  skins,  may 
be  made  white  and  the  coat  preserved,  by  first  taking  a  blunt 
knife  and  scraping  the  skin  on  a  piece  of  circular  wood,  so  as 
to  get  off  as  much  of  the  flesh  and  fat  as  possible  ;  then  make  a 
solution  of  alum,  salt,  and  water,  four  to  one  of  alum,  as  much 
as  the  water  will  contain.  Dissolve  the  alum  in  hot  water, 
when  cold  immerse  the  skin  in  it,  and  in  about  forty-eight 
hours  the  skins  will  be  cured.  Wash  in  a  weak  solution  of 
soda  and  water,  to  carry  off  any  fat  that  may  remain.  If  for 
sheep,  or  other  skins  that  are  thicker,  a  longer  time  will  be 
required.  The  skins  should  be  pulled  about  before  thoroughly 
dry  to  stretch  them.  This  plan  is  a  very  fair  one,  but  is,  of 
course,  not  perfect. 

Bird-Stuffing. — First  dissect  your  specimen.  In  dissecting, 
three  things  only  are  necessary  to  ensure  success,  viz.,  a  pen- 
knife, a  hand  not  coarse  and  clumsy,  and  practice.  In  stuffing^ 
you  require  cotton,  a  needle  and  thread,  a  little  stick,  glass 
eyes,  a  solution  of  corrosive  sublimate,  and  any  kind  of  tem- 
porary box  to  hold  the  specimens.  Wire  is  worse  than  useless, 
as  it  gives  a  stiff  appearance  to  the  object  stuffed.  A  very 
small  proportion  of  the  skull-bone,  say  from  the  fore-part  of 
the  eye  to  the  bill,  is  to  be  left  in,  part  of  the  wing-bones,  the 
jaw-bones,  and  half  of  the  thigh-bones  remain.  Everything 
else — flesh,  fat,  eyes,  bones,  brain,  and  tendons — are  all  to  be 
taken  away.  In  taking  off  the  skin  from  the  body,  it  will 
be  well  to  keep  in  mind  that  you  must  try  to  shove  in  lieu  of 
pulling  it,  lest  you  stretch  it.  Throughout  the  whole  operation, 
as  fast  as  you  detach  the  skin  from  the  body,  you  must  put 
cotton  immediately  betwixt  the  body  and  it ;  this  will  prevent 
the  plumage  getting  dirty.  Let  us  now  proceed  to  dissect 
a  bird.  Have  close  by  you  a  little  bottle  of  corrosive  subli- 
mate, also  a  little  stick,  and  a  handful  or  two  of  cotton.  Now 
fill  the  mouth  and  nostrils  with  cotton,  and  place  it  on  your 
knee  on  its  back,  with  its  head  pointed  to  your  left  shoulder. 
Take  hold  of  the  knife  with  your  two  first  fingers  and  thumb, 
the  edge  upward  ;  you  must  not  keep  the  point  of  the  knife 
perpendicular  to  the  body  of  the  bird,  because,  were  you  to  hold 
it  so,  you  would  cut  the  inner  skin  of  the  belly,  and  thus  let  the 


236  TAXIDERMY. 


bowels  out.  To  avoid  this,  let  your  knife  be  parallel  to  the 
body,  and  then  you  can  divide  the  outer  skin  with  great  ease. 
Begin  on  the  belly  below  the  breast-bone,  and  cut  down  the 
middle,  quite  to  the  vent.  This  done,  put  the  bird  in  any  con- 
venient position,  and  separate  the  skin  from  the  body,  till  you 
get  at  the  middle  joint  of  the  thigh.  Cut  it  through,  and  do 
nothing  more  there  at  present,  except  introduce  cotton  all  the 
way  on  that  side,  from  the  vent  to  the  breast-bone.  Do  exactly 
the  same  on  the  opposite  side.  Now  place  the  bird  perpen- 
dicular, its  breast  resting  on  your  knee,  with  its  back  towards 
you.  Separate  the  skin  from  the  body  on  each  side  of  the  vent, 
and  never  mind  at  present  the  part  at  the  vent  to  the  root  of 
the  tail.  Bend  the  tail  gently  down  to  the  back,  and  while 
your  finger  and  thumb  are  keeping  down  the  detached  parts  of 
the  skin  on  each  side  of  the  vent,  cut  quite  across  and  deep, 
until  you  see  the  backbone  near  the  oil-gland  at  the  root  of  the 
tail.  Sever  the  backbone  at  the  joint,  and  then  you  have  all 
the  root  of  the  tail,  together  with  the  oil-gland,  dissected  from 
the  body.  Apply  plenty  of  cotton.  After  this,  by  shoving 
and  cutting,  get  the  skin  pushed  up  until  you  come  to  where 
the  wing-joints  join  the  body.  Apply  cotton,  and  then  cut  this 
joint  through,  and  do  the  same  at  the  other  wing  ;  add  cotton, 
and  gently  push  the  skin  over  the  head,  cut  out  the  roots  of  the 
ears,  and  continue  skinning  till  you  reach  the  middle  of  the 
eye  ;  cut  the  membrane  quite  through,  otherwise  you  would 
tear  the  orbit  of  the  eye.  After  this  nothing  difficult  inter- 
venes to  prevent  your  arriving  at  the  root  of  the  bill  ;  when  this 
is  effected,  cut  away  the  body,  leaving  just  a  little  bit  of  the 
skull ;  clean  well  the  jaw-bones,  and  touch  the  skull  and  cor- 
responding parts  with  the  solution.  Now  all  that  remains  to 
be  removed  is  the  flesh  on  the  middle  joints  of  the  wings,  one 
bone  of  the  thighs,  and  the  fleshy  root  of  the  tail.  Fasten 
thread  to  the  joints  of  each  wing,  and  then  tie  them  together, 
leaving  exactly  the  same  space  betwixt  them  as  your  knowledge 
in  anatomy  informs  you  existed  there  when  the  bird  was  en- 
tire ;  hold  the  skin  open  with  your  finger  and  thumb,  and  apply 
the  solution  to  every  part  of  the  inside.  Neglect  the  head  and 
neck  at  present  ;  they  will  receive  it  afterwards.  Now  fill  the 
body  moderately  with  wool,  to  prevent  the  feathers  on  the  belly 
from  being  injured.  You  must  recollect  that  half  of  the  thigh, 
or,  in  other  words,  one  joint  of  the  thigh  bone,  has  been  cut 


TAXIDERMY.  237 


away.  As  this  bone  never  moved  perpendicular  to  the  body, 
but,  on  the  contrary,  in  an  obHque  direction,  as  soon  as  it  is 
cut  off  the  remaining  part  of  the  thigh  and  leg,  having  nothing 
now  to  support  them  obliquely,  must  naturally  fall  to  their  per- 
pendicular. Hence  the  reason  why  the  legs  appear  consider- 
ably too  long.  To  correct  this,  take  your  needle  and  thread, 
fasten  the  ends  round  the  bone  inside,  then  push  the  skin  just 
opposite  to  it,  and  then  tack  up  the  thigh  under  the  wings  with 
several  strong  stitches.  This  will  shorten  the  thigh,  and  render 
it  quite  capable  of  supporting  the  body  without  the  aid  of  wire. 
Now  is  the  time  to  put  in  the  cotton  for  an  artificial  body, 
by  means  of  the  little  stick,  and  then  sew  up  the  orifice  you 
originally  made  in  the  belly,  beginning  at  the  vent.  Lastl)', 
dip  your  stick  into  the  solution,  and  put  it  down  the  throat 
three  or  four  times,  in  order  that  every  part  may  receive  it. 
When  the  head  and  neck  are  filled  with  cotton  quite  to  your 
liking,  close  the  bill  as  in  nature.  Bring  the  feet  together  by 
a  pin,  and  then  run  a  thread  through  the  knees,  by  which  you 
may  draw  them  to  each  other,  as  near  as  you  may  judge 
proper.  Nothing  now  remains  to  be  added  but  the  eyes  ; 
adjust  the  orbit  to  them  as  in  nature,  and  that  requires  no  other 
fastener.  After  this,  touch  the  bill,  orbit,  feet,  and  former  oil- 
gland  at  the  root  of  the  tail  with  the  solution,  and  then  you 
have  given  to  the  bird  everything  necessary,  except  attitude  and 
a  proper  degree  of  elasticity.  Procure  any  common,  ordi- 
nary box  ;  fill  one  end  of  it,  about  three-fourths  up  to  the  top, 
with  cotton,  forming  a  sloping  plane.  Make  a  moderate  hol- 
low to  receive  it,  and  place  the  bird  in  its  right  position.  If 
you  wish  to  elevate  the  wings,  do  so,  and  support  them  with 
cotton.  If  you  wish  to  have  the  tail  expanded,  reverse  the 
order  of  the  feathers,  beginning  from  the  two  middle  ones,  and 
when  dry  place  them  in  their  true  order,  and  the  tail  will  pre- 
serve for  ever  the  expansion  you  have  given  it.  In  three  or 
four  days  the  feet  lose  their  natural  elasticity,  and  the  knees 
begin  to  stiffen.  When  you  observe  this,  it  is  the  time  to  give 
the  legs  any  angle  you  wish,  and  to  arrange  the  toes.  When 
the  bird  is  quite  dry,  pull  the  thread  out  of  the  knees,  and  take 
away  the  needle,  and  all  is  done. 

Insects  for  Cases. —  Living  insects,  of  which  you  wish  to 
make  "  objects,"  are  instantly  killed  by  putting  them  into  a  jar 


238  PL  A  N  T-PRESER  VI NG. 

of  carbonic  acid  gas.  This  gives  them  no  pain,  and  leaves 
them  in  the  best  state  for  mounting.  As  soon  as  they  are 
dead,  spread  them  in  the  shape  desired,  and  fasten  them  down 
to  the  box  with  a  corking-pin. 

Skeleton  Leaves. — Skeleton  leaves  may  be  prepared  as 
follows  : — 

1.  Steep  the  leaves  in  rain-water,  in  an  open  vessel,  exposed 
to  the  air  and  sun.  Water  must  occasionally  be  added  to 
compensate  the  loss  by  evaporation.  The  leaves  will  soon 
putrefy,  and  then  their  membranes  will  begin  to  open  ;  now 
lay  them  on  a  clean  white  plate  filled  with  clean  water,  and 
with  gentle  touches  take  off  the  external  membranes,  separating 
them  cautiously  near  the  middle  rib.  When  there  is  an  open- 
ing towards  the  latter,  the  whole  membrane  separates  easily. 
The  process  requires  a  great  deal  of  patience,  as  ample  time 
must  be  given  for  the  vegetable  tissues  to  decay  and  separate. 

2.  A  more  expeditious  method  is  the  following  : — A  table- 
spoonful  of  chloride  of  lime  in  a  liquid  state  mixed  with  a  quart 
of  pure  spring-water.  The  leaves  or  seed-vessels  of  plants 
must  be  soaked  in  the  mixture  for  about  four  hours,  then  taken 
out  and  well  washed  in  a  large  basin  filled  with  water ;  after 
which  they  should  be  left  to  dry,  with  free  exposure  to  light  and 
air.  Some  of  the  larger  species  of  forest  leaves,  or  such  as 
have  strong  ribs,  will  require  to  be  left  rather  more  than  four 
hours  in  the  liquid. 

3.  Perhaps  the  most  effectual  way  is — First  dip  the  leaves 
in  boiling  water,  and  then  immerse  them  in  dilute  sulphuric 
acid,  containing  from  10  to  30  per  cent,  of  the  acid,  according 
to  the  delicacy  or  coarseness  of  the  leaf-structure.  In  a  day 
or  two  use  a  pretty  stiff  bristle  brush  to  the  leaves,  adding  drop 
by  drop  a  little  saturated  solution  of  bichromate  of  potassium. 
When  the  operation  seems  complete,  wash  the  leaves  carefully 
in  ammoniated  water,  and  finish  with  a  little  weak  hypochlorite 
of  calcium  or  chlorine  water. 

4.  Dissolve  3  oz.  of  common  washing-soda  in  a  quart  of  boil- 
ing water,  and  add  i  J  oz.  of  fresh-slaked  quicklime  ;  boil  it  ten 
minutes.  Pour  into  a  pitcher,  and  let  it  stand  a  short  time  till 
settled ;  then  pour  the  clear  solution  again  into  the  pan,  and 
let  it  boil.  Add  the  leaves,  and  boil  for  say  an  hour,  adding 
water  to  supply  that  evaporated.     Take  one  of  the  leaves  out 


PLANT-PRESERVING.  239 

into  a  dish  of  clean  water,  and  rub  it  gently  between  finger  and 
thumb.  If  the  outer  covering  will  leave  the  mid-rib  and  veins, 
they  will  do  ;  if  not,  boil  longer.  Bleach  thus  : — One  drachm 
of  chloride  of  lime  mixed  ia  a  pint  of  water,  and  allowed  to 
settle  ;  pour  off  the  clear  liquid,  and  put  in  the  leaves.  Steep 
them  till  white — say  about  ten  minutes.  If  they  stay  too  long, 
they  become  brittle.  Wash  them  in  a  dish  of  clean  water,  and 
dry  in  a  book  between  blotting-paper. 

When  the  "  skeletons  "  are  obtained  by  either  of  the  four 
processes  given  above,  they  may  be  plated  by  being  dipped  into 
a  very  weak  solution  of  phosphorus  in  bisulphide  of  carbon, 
dried,  placed  in  a  neutral  solution  of  nitrate  of  silver  for  fifteen 
minutes,  dried  again,  and  lastly  covered  with  dead  silver  in  a 
small  electro-plating  apparatus.  An  almost  equally  beautiful 
result  is  produced  if  the  "  skeletons  '^  are  dipped  into  a  clear 
boihng  saturated  solution  of  iodide  of  lead.  When  dry,  they 
appear  as  if  frosted  with  gold.  If  cautiously  painted  with  a 
very  concentrated  alcoholic  solution  of  mauve,  skeleton  leaves 
present  the  appearance  of  a  magnificent  and  delicate  casting  in 
bronze.  It  is  best  to  prepare  leaves  of  one  kind  only  at  a  time, 
as  the  time  it  takes  to  strip  them  differs  considerably.  The 
preparation  of  skeleton  leaves  is  a  very  delicate  and  wearisome 
process,  and  should  only  be  attempted  by  those  happily  con- 
stituted persons  who  can  keep  their  patience  under  repeated 
failures. 

Dried   Flowers  Preserved  in  their  Natural  Colours. — 

Provide  a  vessel  with  a  movable  cover,  and  having  removed 
the  cover  from  it,  fix  over  it  a  piece  of  metallic  gauze  of  mode- 
rate fineness,  and  replace  the  cover.  Then  take  a  quantity  of 
sand  sufficient  to  fill  the  vessel,  and  pass  through  a  sieve  into 
an  iron  pot,  where  it  is  heated,  with  the  addition  of  a  small 
quantity  of  stearine,  carefully  stirred,  so  as  to  thoroughly  mix 
the  ingredients.  The  quantity  of  stearine  to  be  added  is  at  the 
rate  of  half  a  lb.  to  100  lbs.  of  sand.  Care  must  be  taken  not 
to  add  too  much,  as  it  would  sink  to  the  bottom  and  injure  the 
flowers.  The  vessel  with  its  cover  on,  and  the  gauze  beneath 
it,  is  then  turned  upside  down,  and  the  bottom  being  removed, 
the  flowers  to  be  operated  upon  are  carefully  placed  on  the 
gauze  and  the  sand  gently  poured  in,  so  as  to  cover  the  flowers 
entirely,  the  leaves  being  thus  prevented  from  touching  each 


240  AQUARIA. 


other.  The  vessel  is  then  put  in  a  hot  place,  where  it  is  left 
for  48  hours.  The  flowers  thus  become  dried,  and  they  retain 
their  natural  colours.  The  vessel  still  remaining  bottom  up- 
wards, the  lid  is  taken  off,  and  the  sand  runs  away  through  the 
gauze,  leaving  the  flowers  uninjured. 

To  Stock  a  Fresh-Water  Aquarium. — There  ought  to  be 
about  three  plants  to  every  gallon  of  water,  and  two  or  three 
fishes,  according  to  size,  to  every  plant.      Respecting  the 

Fishes  suitable  for  the  aquarium  we  may  make  the  following 
remarks  : — 

Crusian  or  German  Carp  {Cyprijius  ctirassius). — There  are 
two  kinds  of  them  ;  one  is  rather  broader  than  the  other.  Its 
colour  is  gold-like,  and  is  darker  toward  its  tail.  You  ought 
not  to  have  any,  in  a  little  aquarium,  longer  than  two  inches. 
Its  back  is  bream-shaped,  and  it  rises  from  the  nape  to  a  high 
arch  along  the  line  of  the  dorsal  fin.  It  is  a  little  subject  to 
fungoid  growths.  It  will  live  in  dirty  water,  and  is  easily  fed 
with  bread  crumbs  ;  but  you  must  always  be  careful  not  to  give 
it  more  than  it  can  eat  at  once,  because  the  bread  on  the  bottom 
of  the  aquarium  will  render  the  water  impure. 

The  Roach  {Cyprinus  rutihis)  is  very  common. — It  will  also 
live  in  dirty  water,  and  is  very  fit  for  an  aquarium. 

Prussian  Carp  {^Cypi'inus  carpis). — It  is  easily  separated 
from  C.  ctirassius,  through  its  olive-brown  colour,  its  beard 
round  its  mouth,  and  its  tail  and  fins  are  darker.  It  is  not  as 
broad,  but  rounder. 

Gold  Carp  {Cyp7'inus  auratus),  called  so  by  Linnaeus,  the 
celebrated  Swedish  naturalist.  It  originates  from  China,  its 
colour  is  gold,  has  the  shape  of  C.  curassius.  When  it  is 
young  it  is  silverlike.  It  is  nice  to  look  at,  but  very  dull,  and 
difficult  to  tame.  They  sometimes  get  poorly,  and.  are  covered 
with  a  white  mould;,  then  you  must -remove  it  to  a  shallow 
basin,  put  a  little  salt  on  its  back,  and  it  will  soon  rub  the 
mould  off. 

Minnow  {Cyprinus  Phoxinus),  ought  to  be  in  every  aquarium. 
An  aquarium  without  minnows  is  no  aquarium  at  all — it  is  a 
makeshift.  With  a  shoal  of  minnows  and  a  few  Prussian  carp, 
an  aquarium  may  be  considered  fairly  stocked,  because  there  is 
really  something  to  look  at,  something  to  amuse,  and  something 
to  instruct.      They  are  very  shaip  and  amusing,  always  on  the 


AQUARIA.  241 


move  ;  but  it  is  very  strange  that  they  Hve  in  an  aquarium, 
because  you  never  find  them  in  other  than  quite  clean  water 
in  their  wild  state.  Their  lower  parts  have  a  red  colour  during 
the  summer-time,  but  fright  will  make  them  assume  a  pale 
fawn  colour.  The  back  and  the  top  of  the  head  have  a  dark 
olive-green  colour.  It  is  a  little  fish,  but  round.  It  will  never 
grow  longer  than  three  to  four  inches.  You  ought  never  to 
have  any  longer  than  two  inches  in  a  small  tank.  It  is  very 
easy  to  tame ;  you  can  soon  teach  it  to  eat  out  of  your  hand. 

The  Bleak  {Cyprimis  alburnus')  is  also  a  fitting  fish  for  a 
tank,  especially  if  you  pick  small  specimens.  It  is  active  in  its 
movements,  has  a  white,  silverlike  colour,  and  is  continually 
on  the  move. 

Perch  {Cyprinus  fitiviatilis). — You  must  pick  very  small 
specimens.  It  is  a  very  handsome  fish,  but  must  have  quite 
clean  water,  and  can  consequently  not  live  long  in  an 
aquarium. 

Stickleback  (Gasterostetis). — Should  never  be  put  into  an 
aquarium  with  other  small  fishes.  They  are  greedy  and  un- 
easy, and  scarcely  ever  let  the  other  fishes  alone,  often  killing 
several.  They  must  therefore  be  kept  in  a  tank  by  themselves, 
or  where  there  are  only  large  fishes.  They  are,  however,  very 
interesting.  Dr  Lankaster,  speaking  of  this  fish,  says  : — "  He 
has  all  the  ways  of  other  fishes,  and  many  more  besides.  Look 
into  your  tank ;  see,  there  is  one  larger  than  the  rest ;  he  is 
clothed  in  a  coat  of  mail  like  a  knight  of  old,  and  it  is  resplen- 
dent with  purple  and  gold.  See  how  his  eyes  glisten,  and  with 
every  movement  present  a  new  colour.  He  is  a  male  fish,  the 
king  of  your  little  shoal.  He  has  important  offices  to  perform. 
Presently,  in  the  course  of  a  few  days,  if  you  watch  him,  and 
are  fortunate,  you  will  see  this  wonderful  little  fish  engaged  in 
the  most  useful  manner  in  building  a  nest.  He  first  seizes 
hold  of  one  little  bit  of  weed,  then  of  another,  and  carries  them 
all  to  some  safe  corner,  till  at  last  his  nest  is  built.  Having 
done  this,  he  gently  allures  his  mate  to  his  new-made  home. 
Here  she  deposits  her  eggs,  and  having  done  this,  resigns  the 
care  of  them  to  our  hero  of  the  purple  and  gold,  who  watches 
over  them  with  an  anxiety  that  no  other  male  in  creation  but 
the  male  stickleback  seems  to  know.  He  fans  and  freshens 
the  water  with  his  fins,  and  at  last,  when  the  young  are  hatched, 
watches   over  their  attempts  at  swimming  with  the  greatest 

Q 


242  AQUARIA. 


anxiety.  Nor  is  this  habit  confined  to  the  fresh-water  stickle- 
backs. A  lady,  writing  to  me  from  Aberdeen,  and  describing 
her  aquavivarium,  says,  '  A  fifteen-spined  stickleback  ( Gas- 
terosteus  spinachia)  constructed  a  nest  on  a  piece  of  rock 
which  was  covered  with  a  fine  green  seaweed,  depositing  the 
spawn  first,  then  covering  it  with  loose  seaweed,  and  lacing  all 
together  with  a  long  thread,  composed,  apparently,  of  some 
secretion.  The  fish  afterwards,  for  about  the  space  of  three 
weeks,  watched  the  nest,  never  leaving  it  at  all  save  for  the 
purpose  of  driving  away  the  other  fish  when  they  approached 
too  near.  When  a  stick  was  introduced  into  the  vicinity  of  the 
nest,  the  fish  would  fly  open-mouthed  to  attack  it,  and  would 
bite  it  with  great  apparent  fury.  At  the  expiration  of  the 
above-named  time,  the  young  fry  made  their  appearance  by 
hundreds,  but  I  am  sorry  to  say  they  soon  disappeared,  being 
devoured  by  the  other  fish,  and  caught  by  the  tentacles  of  the 
sea-anemones.  The  mother-fish  continued  her  attendance  at 
the  nest  as  long  as  any  of  the  young  fry  were  left.'  " 

If  you  see  your  fishes  go  up  to  the  surface  of  the  water  in 
your  aquarium,  you  have  too  many  fishes ;  so  you  must  either 
take  away  some,  or  put  in  some  more  plants.  If  you  then  find 
that  the  glass  sides  commence  to  be  green,  you  are  obliged  to 
put  in  some  snails  or  molluscs,  which  will  in  a  short  time  clean 
the  glass  ;  but  if  you  put  in  too  many,  they  will  commence  to 
eat  the  plants,  and  then  you  have  to  remove  some  of  them, 
especially  Linjicsus  stagttalis^  because  that  one  likes  the  plants 
better  than  the  green  moss  on  the  glass.  The  best  wood  of 
which  to  construct  an  aquarium  is  East  India  teak.  It  is 
generally  very  evenly  grained,  easily  cleaned  up  for  polishing, 
and,  all  things  considered,  it  seems  the  most  suitable.  It  may 
be  obtained  at  shipbuilding  establishments,or  of  coach-builders, 
at  a  little  over  the  price  of  mahogany. 

The  Size. — For  a  small  room,  one  to  hold  ten  or  twelve 
gallons  of  water  is  a  good  size.  Suppose  we  get  a  piece  for 
the  bottom  2  ft.  long  by  14  in.  broad,  to  finish  i  in.  clear  in 
thickness,  and  4  ft.  4  in.  to  finish  i  j  in.  square  for  the  pillars. 
We  yet  require  a  piece  for  the  top  frame  6  ft.  4  in.  long,  2^ 
in.  by  \  in.  thick.  This  is  all  the  timber  required  for  the 
tank.  After  planing  up  the  bottom  and  squaring  the  sides 
and  ends,  run  a  cutting  guage  round  it  if  in.  from  the  outside. 
This  is  the  outside  of  the  glass  ;   then  again  a  \  in.  within,  to 


AQUARIA, 


243 


allow  for  the  composition  with  which  the  glass  is  fixed.  The 
groove  must  be  a  ^  in.  or  ^  in.  deep.  Next  guage  |  in.  from 
the  edge  for  the  distance  the  vase  mould  is  worked  back.  The 
pillars  to  be  planed  up  to  if  in.  square,  and  grooved  on  two 
sides  in  the  centre  -^  in.  deep,  allowing  the  same  for  compo- 
sition as  in  the  bottom.  This  groove  must  be  carefully  filled 
up  with  a  piece  of  deal  before  turning,  and  the  length  must  be 
to  show  12  in.  of  glass.  Some  care  must  be  taken  not  to  sink 
too  much  in  turning,  so  as  to  get  to  the  bottom  of  the  groove. 
Leave  a  square  i^  in,  at  the  bottom,  and  |  in.  at  the  top.  The 
pillar,  to  get  the  tank  water-tight,  ought  to  be  tenoned  into  the 
bottom  I  in.  deep.  The  best  proportion  of  an  aquarium  is 
that  the  length  ought  to  be  double  the  width,  and  the  height 
equal  to  the  width  ;  as,  for  example,  if  the  length  be  2  feet,  the 
height  and  width  should  be  i  foot.  There  ought  to  be  neither 
paint  nor  varnish  inside  the  aquarium  ;  they  are  injurious  to 
the  fish.  The  best  time 
of  the  year  for  making  an 
aquarium  is  April,  May, 
or  the  beginning  of  June, 
because  the  fish  and  in- 
sects are  very  still  in  the 
cold  season,  so  that  they 
are  accustomed  to  the 
small  space. 

A  gentleman,  with  some 
years'  experience  of  a  40- 
gallon  aquarium,  says  that  zinc  or  iron  should  be  most  strictly 
kept  out  of  contact  with  the  water ;  iron  is  bad  for  the  plants, 
and  zinc  is  poisonous  to  the  fish;  the  metal,  being  always  im- 
pure, is  dissolved  more  or  less.  You  can  try  a  varnish  made  by 
dissolving  marine  glue  in  wood  naphtha  made  thin,  and  allowed 
to  dry  down  to  necessary  consistence.  This  form_s  a  capital 
varnish  for  the  joints  of  aquarium  over  the  lead  cement.  The 
varnish  should  be  laid  on  thin  for  the  first  coat,  as  it  then  runs 
into  small  crevices  ;  each  coat  to  stand  a  day.  All  lac  var- 
nishes are  attacked  by  the  ammonia  in  the  water.  Should  it 
be  impossible  to  empty  the  tank  or  take  out  pipe,  you  might 
try  a  brass  tube  just  large  enough  to  drop  over  iron  and  zinc 
pipe,  an  indiarubber  ring  at  bottom  coming  just  below  edge  of 
brass  tube  to  exclude  current  of  water  setting  up  between  the 


LNDI_A. 

IRON 

RUBBCn 

1 

244 


AQUARIA. 


tubes  ;  or,  perhaps  better  still,  a  piece  of  indiarubber  tubing 
slipped  over  the  iron  and  zinc  pipe.  Portland  cement  is  also 
injurious  to  fish.  Roman  cement  should  be  exclusively  used 
for  rock-work,  which  should  be  soaked  in  water  for  a  month 
before  being  placed  with  the  fish. 

Aquarium  Fountain. — A  table  or  aquarium  fountain  may- 
be made  thus  : — The  design  is  simple,  requiring  no  piston, 
weights,  or  other  mechanism  ;  it  is,  in  fact,  a  "  syphon  with  an 
enlarged  bend."     The  experiment  was  first  tried  with  a  pickle 


bottle  and  two  bits  of  tube.  The  air  must  be  sucked  out  till 
the  water,  rising  through  vz  out  of  the  jug  c,  begins  to  run  down 
the  tube  b  ;  the  fountain  will  then  play  till  all  the  water  in  c  is 
exhausted,  or  as  in  the  second  engraving  (representing  the 
actual  fountain).  A  is  a  glass  shade  fitted  air-tight  into  a  tray 
of  tin,  or  other  material ;  ^  is  a  tube  with  a  nozzle,  having  a 
hole  about  l  - 1 6th  of  an  inch  ;  a  piece  of  glass  tube  drawn  to 
a  point  will  do  very  well ;  the  lower  end  should  nearly  touch 


AQUARIA. 


245 


A,  the  water  consequently  rises 


the  aquarium,  or  other  reservoir ;  ^  is  a  tube,  the  top  of  which 
should  be  nearly  flush  with  the  tray  as  shown ;  say  6  in.  may 
be  metal  or  glass, 
the  rest  may  be 
elastic,  or  any  other 
tube,  and  may  con- 
vey the  waste  water 
through  the  bottom 
of  the  aquarium,  or 
over  the  top,  or  out 
of  a  window.  The 
weight  of  the  water 
in  the  longer  arm 
of  the  syphon  b 
produces  a  partial  vacuum 
through  a. 

1.  In  this  plan  the  pipe  conveying  the 
water  from  the  piston  to  the  jet  is  india- 
rubber,  fastened  to  a  piece  of  brass  tubing 
about  i\  in.  long  on  top  of  piston,  the 
other  end  being  fastened  to  the  jet-pipe, 
as  shown  in  present  sketch.  The  run- 
ning of  water  is  also  shown.  IT,  india- 
rubber  tube,  connecting  JP,  jet-pipe,  with 
top  of  piston.  WP,  waste-pipe,  convey- 
ing the  water  from  B  down  outside  of 
jet-pipe  to  cylinder.  It  may  be  open  or 
closed  at  top  ;  if  closed,  the  cap  must  be 
drilled  full  of  little  holes.  The  water  in 
B  has  to  rise  to  top  of  this  waste-pipe, 
thus  keeping  a  good  supply  of  water  for 
fish.  The  tube  WP  may  be  hidden  by 
artificial  rocks. 

2.  In  this  diagram,  A  is  a  porcelain 
or  other  basin,  B  and  C  are  two  glass 
globes  connected  by  two  tubes  D  and  F, 
of  which  D  commences  near  the  top  of 
the  upper  globe,  and  ends  near  the  top 
of  the  lower  one ;  and  F  commences  at 
L  in  the  basin  A,  and  ends  near  the  bottom  of  the  lower  globe. 
The  third  tube  E  commences  in  the  jet  at  J,  and  ends  near  the 


246 


MISCELLANEOUS  CHEMICAL  PROCESSES 


bottom  of  the  upper  globe.  G  is  a  plug  fastened  by  a  string 
at  K;  H  is  a  stopcock  leading  out  of  the  lower  globe  to  the 
outside  of  the  aquarium  ;  WW  is  water.  This  fountain  is 
placed  in  the  aquarium  till  the  water  is  a  little  above  the  vessel 
A.  When  you  wish  it  to  play,  pull  out  the  plug  G,  and  open 
the  stopcock  H  ;  the  water  then  rushes  in  at  G  till  it  is  nearly 
level  with  the  top  of  the  tube  D,  and  then  the  plug  G  is  re- 
placed, the  stopcock  H  is  closed,  and  the  jet  J,  which  must  also 

have  a  stopcock,  is 
opened ;  the  water 
then  rushes  down  the 
tube  F  into  the  lower 
globe,  the  water  forces 
the  air  up  the  tube  D 
into  the  upper  globe, 
and  the  compressed 
air  forces  the  water 
in  the  upper  globe 
through  the  tube  E, 
and  through  the  jet  J. 
Then  when  the  water 
in  B  is  exhausted, 
shut  up  the  jet,  pull 
out  the  plug  G,  and 
open  the  stopcock  H, 
&c. 

Spirit  Blow-Pipes. 

—  Two  spirit  blow- 
pipes, figs.  I  and  2, 
are  described  below  : 
Fig.  I  has  a  boiler,  A, 
made  of  copper,  in 
the  most  suitable 
shape.  It  must  be 
air-tight.  B  is  a 
safety-valve,  which  is 
kept  close  by  a  spiral 
spring  inside.  The  valve  B  must  be  made  with  a  socket,  the 
socket  being  brazed  on  top  of  boiler  ;  it  must  be  made  to  screw 
off  and  on  ;  a  pipe,  D,  must  then  be  brazed  in  at  the  top,  a  stop- 


AND  COMPOSITIONS. 


247 


cock,  C,  must  be  put  on  the  pipe,  and  another  pipe,  Dl,  must  be 
connected  on  the  end  of  stopcock,  and  brought  a  little  more  than 
half-way  under  the  bottom  of  boiler.      If  required  for  making 
gasfitters'  joints,  a  small  round  hole  in  the  end  G  will  answer 
best ;  if  for  melting  sheet-brass,  the  end  made  flat  will  do.      It 
would  be  a  good  plan  to  get  jets  to  screw  on  and        p, 
off.     A  socket  should  be  brazed  on  the  side,  with     oMpn-  *^^ 
a.  piece  of  iron  tapped  into  it ;   the  piece  of  iron        []~ 
should  be  tapped  at  both  ends,  and  a  socket  with 
a  thumbscrew  made  to  screw  on  to  it.      A  piece  of  round  bar- 
iron  or  gas-pipe  should  be  put  for  a  slide  F,  and  a  piece  of 
sheet  iron  should  be  put  at  the  bottom  for  F  to  be  fixed  into, 
and  for  the  lamp  H  to  stand  on.     I  is  a  regulator  to  turn  the 
wick  up  and  down. 

FIC.2. 


A  vent-hole  should 
be  left  in  the  top 
of  lamp,  the  boiler 
should  be  filled  up 
to  within  i  inch  of 
the  top  with  methy- 
lated spirits,  and 
the  lamp  may  be 
filled  with  the  same. 
Care  must  be  taken 
to  have  everything 
sound,  and  an  in- 
diarubber  washer 
should  be  put  on 
the  under  side  of 
rim  of  safety-valve; 
the  valve  can  be 
taken  out  to  put 
spirits  in.  Stop- 
cocks can  be  got 
about  I  in.  long. 

Fig.  2  is  another 
style  of  blow-pipe. 
A  frame  of  sheet  iron  is  made  similar  to  a  pint  pot,  only  the 
lower  part  of  the  front  is  cut  away  to  make  room  to  put  the 
lamp  H  in,  and  to  allow  the  flame  to  come  out.  A  is  the 
boiler,  made  of  two  pieces  of  copper,  with  both  edges  closed  to 


248  MISCELLANEOUS  CHEMICAL  PROCESSES 

form  a  rim  outside  ;  the  boiler  should  be  made  to  fit  the  frame, 
a  safety-valve,  B,  should  have  a  socket  brazed  in  at  the  top  of 
boiler ;  the  valve  must  be  made  to  screw  in  and  out.  A  spiral 
spring  must  be  put  to  keep  the  valve  closed  ;  a  pipe,  D,  must 
be  put  in  as  near  the  top  as  possible ;  a  stopcock,  C,  must  be 
put  as  near  as  it  can  be,  so  as  to  come  above  the  frame  that 
holds  the  lamp  and  boiler  ;  a  pipe,  Dl,  must  be  put  to  conduct 
the  gas  down  to  the  bottom,  a  little  more  than  half-way  under 
the  boiler ;  a  lamp,  H,  must  then  be  put  under,  leaving  about 
an  inch  between  the  boiler  and  lamp.  A  small  hole  must  be 
made  in  the  back  of  the  frame  for  the  regulator  I  to  come 
through;  the  pipe  should  terminate  the  same  as  in  fig.  i ;  a  small 
ring  should  be  put  on  the  bottom  of  fig.  2  of  the  lamp  to  draw 
it  out  when  required.  Both  boilers  must  be  supplied  by  taking 
out  the  safety-valve,  and  nearly  filled  with  methylated  spirits. 

A  Spirit  Blow-pipe,  made  on  either  of  the  above  plans, 
effects  a  considerable  saving  of  spirits.  On  lighting  the  lamp, 
the  cock  can  be  turned  off  till  the  spirits  are  hot ;  it  can  then 
be  turned  on,  and  the  flame  can  be  regulated  as  required. 

Spirit  Blow-Pipe» — It  is  all  copper,  and  cyhndrical ;  but 
shown  in  section  with  lid  on.      The  pipe  or  tube,  as  will  be 
seen,  forms  the  handle,  and  is  put  in 
f  operation  by  igniting  the  spirits,  which 

"~":^^^^::::~^^  are  up  to  the  dotted  lines,  and  extin- 

(r^  "^N\       guished  by  simply  putting  on  the  lid  ; 

jj  it  can  be  made  to  meet  the  require- 
I  "\—.^^^  ments  of  almost  any  class  of  artizan. 
l-''i"^~"  ~^~^^^^^^===^  It  is  very  simple,  compact,  easy  to 
manage,  and  stands  on  its  own  bottom. 
By  connecting  another  vessel  for  the  regular  supply  of  spirits, 
it  can  be  kept  going  for  any  length  of  time,  and  by  other  simple 
arrangements  the  flame  can  be  placed  in  any  direction. 

Amateur's  Gas  Blow-Pipe. — This  may  be  easily  con- 
structed. All  that  is  requisite  is  a  common  blow-pipe  and  a 
piece  of  brass  tube  about  3- 1 6ths  of  an  inch  in  diameter.  Bend 
the  tube  slightly  at  one  end,  and  at  the  shoulder  make  a  hole 
so  that  the  small  end  of  the  blow-pipe  may  pass  through  into 
the  larger  tube,  to  come  about  flush  with  its  end.  Solder  the 
joint  to  make  it  air-tight,  and  fasten  pieces  of  vulcanized  india- 
rubber  tube  of  any  convenient  length  to  each  of  the  other  ends 


AND  COMPOSITIONS. 


249 


of  the  brass  tubes,  and  the  instrument  is  complete.  Let  gas 
pass  through  the  larger  tube  and  ignite  it ;  now  blow  through 
the  blow-pipe,  and  by  regulating  the  gas-flame  you  can  easily 
obtain  any  degree  of  heat  you  wish,  as  well  as  a  very  steady 
flame  of  any  shape. 
Few  who  have 
once  used  it  will 
willingly  go  back 
to  the  single  tube 
or  ordinary  blow- 
pipe. The  fine 
end  of  the  blow- 
pipe should  be 
about  the  centre  of 
the  larger  or  gas 
tube. 


Matches  without  Phosphorus.  —  The  following  mixtures 
will  be  found  to  answer  satisfactorily  : — i.  Divide  a  solution 
of  copper  into  two  equal  parts  ;  supersaturate  one  with  am- 
monia and  the  other  with  hyposulphate  of  soda ;  mix  them 
together,  and  dry  the  precipitate,  which  will  fall.  Mix  this 
with  strong  glue  and  a  small  quantity  of  powdered  glass. 
Lucifers  made  with  this  mixture  will  ignite  on  any  rough  sur- 
face. 2.  Take  from  four  to  six  parts  of  chlorate  of  potash, 
and  two  parts  each  of  bichromate  of  potash,  and  of  oxide  of 
iron  or  lead,  and  mix  with  three  parts  of  strong  glue.  For  an 
igniting  surface,  take  from  four  to  six  parts  of  oxide  of  either 
iron,  lead,  or  manganese,  two  parts  of  glass -powder,  and  from 
two  to  three  parts  of  strong  glue  or  gum.  These  matches  will 
ignite  only  on  the  friction  surface  thus  prepared.  Another 
German  chemist  uses  for  the  match-heads  a  mixture  of  chlorate 
of  potash  and  a  salt  which  he  describes  as  a  compound  of 
hyposulphurous  acid  with  soda,  ammonia,  and  oxide  and  sub- 
oxide of  copper.  He  forms  this  compound  by  dividing  a  solu- 
tion of  copper  into  two  equal  parts,  supersaturating  one  of  them 
with  ammonia,  and  the  other  with  hyposulphate  of  soda  \  then 
mixing  the  two  solutions,  and  stirring  the  mixture  well.  A 
violet  powder  precipitates  ;  one  part  of  it  is  to  be  mixed  with 
two  parts  of  the  chlorate  of  potash,  and  a  small  quantity  of 
pounded    glass.       Lucifers  made  in   this   way,   however,  will 


250  MISCELLANEOUS  CHEMICAL  PROCESSES 

ignite  on  any  rough  surface,  even  more  easily  than  the  common 
kind. 

Use  of  Alum  in  Iron  Safes. — In  fire-proof  safes  there  is 
a  certain  space  filled  with  powdered  alum.  When  the  heat 
reaches  this,  the  water  of  crystallization  is  driven  off,  by  which 
a  great  absorption  of  heat  is  produced,  and  the  temperature  of 
the  interior  of  the  safe  kept  proportionately  low.  This  is  the 
principle  of  Milner's  safe. 

Chlorate  of  Potash. — Mix  3  lbs.  of  common  salt,  2  lbs.  of 
manganese  at  8d.  or  9d.,  and  2  lbs.  by  weight  of  oil  of  vitriol, 
previously  diluted  with  about  2  pints  of  water,  and  allowed  to 
cool ;  distil  into  a  retort  containing  6  oz,  pearl  ash,  dissolved 
in  3  lbs.  of  water ;  when  the  distillation  is  finished,  evaporate 
the  liquid  in  the  receiver  slowly  in  the  dark.  The  chlorate 
will  crystallize  in  flakes.  Of  course  these  quantities  may  be 
altered  to  suit  the  convenience  of  the  operator. 

Spontaneous  Combustion  of  Oil  Rags. — When  cotton  waste 
or  shavings  are  saturated  with  oil,  a  large  surface  is  exposed 
to  the  action  of  the  air  ;  and  if  the  oil  has  the  property  of 
absorbing  oxygen,  it  may  absorb  the  gas  so  rapidly  as  to  take 
fire.  This  is  the  way  in  which  spontaneous  combustion  takes 
place.  As  petroleum  naphtha  does  not  absorb  oxygen,  it  never 
takes  fire  by  spontaneous  combustion. 

Lubricating  Composition. —  Good  lard,  16  oz. ;  bees'-wax,  2 
oz.  ;  olive  or  sperm  oil,  40  oz.  ;  flowers  of  sulphur,  8  oz. ;  black- 
lead,  4  oz.  (in  powder,  and  free  from  grit)  ;  white  soap,  i  oz.  ; 
all  of  the  best  quality,  and  to  be  well  incorporated. 

Crucibles  of  Lime. — In  these  experiments  a  clay  crucible 
of  somewhat  larger  capacity  than  the  desired  lime  one  is  filled 
with  common  lampblack,  compressing  the  same  by  stamping- 
it  well  down.  The  centre  is  then  cut  out  with  a  knife  until  a 
mere  shell  or  lining  of  lampblack  is  left  firmly  adherent  to  the 
sides  of  the  crucible,  and  about  half  an  inch  or  less  in  thick- 
ness, according  to  the  size  of  the  crucible  ;  this  lining  is  now 
well  rubbed  down  with  a  thick  glass  rod  until  its  surface  takes 
a  fine  glaze  or  polish,  and  the  whole  cavity  is  then  filled  up 
with  finely-powdered  caustic  lime,  and  pressed  down  as  before, 
and  a  central  cavity  cut  out  as  before  ;  or  the  lime-powder  may 


AND  COMPOSITIONS. 


251 


be  at  once  rammed  down  round  a  central  core  of  the  dimen- 
sions of  the  intended  lime  crucible.  This  lime  lining  is  natu- 
rally rather  soft  before  being  placed  in  the  furnace,  but  upon 
heating  agglutinates,  and  forms  a  strong  and  compact  crucible, 
which  is  prevented  acting  upon  the  outer  one  by  the  interposed 
thin  lampblack  layer,  and  at  the  end  of  the  experiment  gene- 
rally turns  out  as  solid  and  compact  as  those  made  in  the  lathe. 
Experiments  made  with  such  crucibles,  even  up  to  dimensions 
containing  several  pounds  of  metal,  have  proved  them  extremely 
well  suited  for  these  operations,  and  doubtless  similar  crucibles 
could  be  made  lined  with  magnesia  or  alumina  as  required. 
In  some  cases  ordinary  blacklead  crucibles,  lined  with  pow- 
dered lime,  magnesia,  or  alumina,  might  possibly  be  found  to 
answer. 

Chemical  Balance. — A  thin  piece  of  fir-wood,  not  thicker 
than  a  shilling,  and  a  foot  long,  and  }j  in.  broad,  is  divided 
into  twenty  parts — that  is,  ten  parts  on  each  side  of  the  middle; 
these  are  the  prin- 
cipal divisions,  and  '''^  ' 
each  of  them  is  sub- 
divided into  halves 
and  quarters ;  across 
the  axis  is  fitted 
one  of  the  smallest 
needles,  and  fixed  to 
its  place  by  sealing- 
wax.  The  fulcrum 
is  a  piece  of  brass, 
the  middle  of  which 
lies  flat  upon  the  table.  The  two  ends  are  bent  at  right  angles, 
so  as  to  stand  upright,  and  are  ground  flat  upon  a  hone.  They 
stand  above  the  surface  of  the  table  only  i-sth  of  an  inch.  This 
balance  will  weigh  the  minutest  quantity,  even  the  1200th  of  a 
grain.  A  grain  weight  is  placed  on  one  division,  and  the  object 
on  the  other  ;  the  proportion  of  the  two  will  indicate  the  weight 
of  the  latter.  The  other  is  on  the  same  principle  ;  the  scales 
are  of  ivory,  from  which  a  small  bullet  is  suspended  by  a  wire  ; 
the  process  of  weighing  as  in  the  former  balance. 

LaugMng  Gas. — Laughing  gas^  (nitrous  oxide)  is  prepared 
from  nitrate  of  ammonia  by  heating  it  in  a  glass  retort,  or  in  a 


252 


MISCELLANEOUS  CHEMICAL  PROCESSES 


clean  dry  Florence  flask,  with  a  bent  glass  tube  attached.  The 
stem  of  the  retort  or  tube  must  dip  into  a  pneumatic  trough, 
on  the  shelf  of  which  the  jar  to  collect  the  gas  is  placed.  A 
solution  of  2  oz.  of  sulphate  of  iron  in  one  gallon  of  water, 
warm,  should  be  used  in  lieu  of  water,  as  it  purifies  the  gas. 
On  the  application  of  heat,  the  gas  passes  over  into  the  jar, 

driving,  of  course, 
the  water  out.  An 
ordinary  gas  jar  will 
do  to  collect  the 
gas,  in  the  mouth 
of  which  a  cork, 
with  a  piece  of 
glass  tubing,  with 
anindiarubber  pipe 
attached,  passed 
through  it,  is  in- 
serted. A  stopcock  must  be  attached  to  the  pipe  to  prevent 
the  escape  of  gas  till  wanted. 

To  mhale. — Place  the  tube  in  the  mouth,  empty  the  lungs  of 
air,  stop  the  nostrils  with  the  fingers,  and  then  inhale  the  gas, 
say  for  a  few  seconds.  The  effects  vary  with  the  constitution. 
Combative  people  should  not  take  it,  nor  should  it  be  adminis- 

E  tered    to    females. 

The  source  of  heat 
must  be  withdrawn 
immediately  any 
white  fumes  appear 
in  the  retort ;  and 
care  should  be 
taken  to  .  control 
those  under  the  in- 
fluence of  this  gas, 
as  they  are  then 
utterly  unable  to 
do  so  themselves. 
The  frequent  use  of 
nitrous  oxide  is  not 
conducive  to  health.  A,  retort ;  B,  Florence  flask ;  C,  pneu- 
matic trough ;  D,  gas  jar.  a,  spirit-lamp ;  b^  stopcock ;  Cj 
conducing  pipe  ;   d,  shelf  of  strength. 


AND  COMPOSITIONS. 


253 


Another  mode  of  preparing. — An  ordinary  retort,  purchasable 
at  any  glass-house,  is  shown  at  A.  The  stand  for  the  retort  is 
seen  at  B,  with,  C,  a  screw  to  fix  the  ring  in  which  the  retort 
rests;  D  is  the  spirit-lamp;  E  is  a  bottle  containing  water,  into 
which  the  gas  rises,  having  escaped  at  the  mouth  of  the  retort 
at  y,  and  passes  through  the  water  in  the  trough  F  into  the 
bottle  E,  in  little  bubbles,  driving  the  water  out  of  the  bottle 
as  the  gas  rises  to  the  top  ;    GGGGG  is  a  table  of  triangular 


form. 


be 


supporting  the  trough  F.  Into  the  retort  A  must 
placed  some  of  the 
salt  called  nitrate  of 
ammonia ;  then  set 
light  to  the  spirit- 
lamp  under  the  retort 
or  Florence  flask  ;  a 
gas  will  be  given  off 
which  will  pass  down 
the  tube  of  the  retort, 
under  the  water,  and 
thence  rise  into  the 
bottle,  forcing  the 
"water  out  as  it  rises. 
This  process  of  collecting  gas  is  called  "  collecting  over  water." 
When  the  bottle  is  perfectly  empty  of  water,  it  is  full  of  nitrous 
oxide — the  gas  required  ;  and  in  taking  the  bottle  from  the 
water,  the  stopper  should  be  placed  in  before  letting  the  mouth 
of  the  bottle  come  beyond  the  surface  of  the  water,  or  else  the 
gas  will  escape.  As  many  bottles  of  gas  as  are  required  can  be 
prepared  in  this  manner. 

Laughing  gas  is  now  used  as  an  anodyne  by  the  dentists. 


Nitrate  of  Potash. — New  Process. — It  has  been  ascer- 
tained, by  M.  Condurie,  that  nitrate  of  potash  may  be  formed 
from  nitrate  of  soda,  by  a  very  simple  process.  This  consists 
in  mixing  concentrated  and  equivalent  solutions  of  nitrate  of 
soda  and  chloride  of  barium,  or  sulphate  of  baryta,  which  pre- 
cipitates the  sparingly  soluble  nitrate  of  baryta  :  washing  the 
latter  and  boiling  it  with  sulphate  of  lead,  which  forms  nitrate 
of  lead  and  sulphate  of  baryta  ;  and  boiling  the  nitrate  of  lead 
with  sulphate  of  potash,  which  forms  the  required  nitrate  of 
potash,  and  reproduces  the  sulphate  of  lead. 


254  MISCELLANEOUS  CILEZMICAL  PROCESSES 

To  Clarify  Impure  Water. — The  chemical  agent  to  effeet 
this  object  is  a  solution  of  the  neutral  sulphate  of  peroxide  of 
iron  (Fe^,  O3,  x  3  SO3),  which  is  to  be  added,  in  a  very  diluted 
state,  to  the  water  intended  to  be  operated  upon. 

The  proportion  in  which  the  solution  of  neutral  sulphate  is 
to  be  added  to  the  water,  for  the  purpose  of  the  invention, 
must  be  determined  by  the  amount  of  the  impurity  contained 
therein.  The  suitable  proportions  must  therefore  be  ascertained, 
by  careful  experiment  carried  on  from  time  to  time,  if  it  should 
be  found  that  the  impurity  of  the  water  varies.  The  addition  of 
more  or  less  of  the  neutral  sulphate  will  not  materially  affect 
the  process  beyond  the  evident  fact,  that  too  dilute  a  solution 
of  the  salt  would  probably  either  leave  some  of  the  impurities 
in  the  water,  or  the  purifying  process  would  be  more  costly 
than  would  be  necessary  for  the  complete  success  of  the 
process. 

The  water  to  be  purified  may  be  run  into  a  tank  or  reser- 
voir, and  the  solution  of  neutral  sulphate  added  thereto  as  it 
runs  in,  so  that  the  solution  may  be  well  mixed  with  the  water 
to  be  purified.  A  short  time  after  the  neutral  sulphate  is  added 
to  the  impure  water  it  becomes  decomposed,  and  forms,  with 
some  of  the  impurities  contained  in  the  water,  a  basic  salt, 
which  is  insoluble  in  water.  The  sohd  and  insoluble  particles 
of  this  new  salt  are  precipitated,  and,  together  with  the  im- 
purities contained  in  the  water,  form  a  sedimentary  deposit, 
from  which  the  purified  water  may  be  allowed  to  run  off,  leav- 
ing behind  the  sedimentary  deposit  in  the  tank  or  reservoir. 
A  repetition  of  this  precipitation  process  on  other  bodies  of 
water  which  may  be  run  into  the  same  tank  or  reservoir  will 
cause  additional  deposits,  which,  when  they  have  been  allowed 
to  accumulate  to  a  sufficient  depth  in  the  reservoir,  may  be 
collected,  and  removed  from  the  reservoir  from  time  to  time. 
This  process  has  been  patented  by  Mr  Edward  Newton. 

Refining  Olive  Oil. — The  best  olive  oil,  in  its  crude  state, 
possesses  that  pecuhar  bland  flavour  which  fits  it  for  the  table, 
and  which  appears  to  arise  principally  from  the  quantity  of 
mucilage  and  water,  either  held  in  solution,  or  mechanically 
mixed  with  it.  By  keeping  one  or  two  years  in  jars,  a  consi- 
derable portion  of  the  mucilage  and  water  subsides,  which 
renders  such  oil  not  only  cheaper,  but  better  qualified  for  yield- 


AMD  COMPOSITIONS.  255 

ing  a  greater  proportion  of  pure  oil  than  that  which  is  recently 
expressed  from  the  fruit.  Two  or  three  gallons  skimmed  from 
the  surface  of  a  large  jar  that  has  remained  at  rest  for  twelve 
months  or  upwards  is  preferable  to  any  succeeding  portion  from 
the  same  jar,  and  may  be  considered  the  cream  of  the  oil. 
Having  procured  good  oil  in  the  first  instance,  put  about  one 
gallon  into  a  cast-iron  vessel  capable  of  holding  two  gallons  ; 
place  it  over  a  slow,  clear  fire,  keeping  a  thermometer  sus- 
pended in  it;  and  when  the  temperature  rises  to  220°,  check 
the  heat,  never  allowing  it  to  exceed  230°,  nor  descend  below 
212,  for  one  hour,  by  which  time  the  whole  of  the  water  and 
acetic  acid  will  be  evaporated.  The  oil  is  then  exposed  to  a 
temperature  of  30°  to  36°  for  two  or  three  days  (consequently 
winter  is  preferable  for  the  preparation,  as  avoiding  the  trouble 
and  expense  of  producing  artificial  cold).  By  this  operation  a 
considerable  portion  is  congealed  ;  and  while  in  this  state, 
pour  the  whole  on  a  muslin  filter,  to  allow  the  fluid  portion  to 
run  through  ;  the  solid,  when  re-dissolved,  may  be  used  for 
common  purposes.  Lastly,  the  fluid  portion  may  be  filtered 
once  or  more  through  newly-prepared  animal  charcoal,  grossly 
powdered,  or  rather  broken,  and  placed  on  bibulous  paper  on 
a  wire  frame,  within  a  funnel,  by  which  operation  rancidity 
(if  any  be  present)  is  entirely  removed,  and  the  oil  is  rendered 
perfectly  bright  and  colourless. 

Refining  Lard  Oil. — Bancroft's  Process. — Stir  the  oil  with 
a  lye  of  caustic  potash  of  the  specific  gravity  of  i  "Z.  A  suffi- 
cient quantity  has  been  added  when  a  portion  begins  to  settle 
down  at  the  bottom.  After  twenty-four  hours  the  clear  oil 
should  be  decanted  from  the  soapy  sediment  and  filtered.  It 
may  be  bleached  by  using  a  saturated  solution  of  hydrochloric 
acid  with  bichromate  of  potash. 

Petroleum  Stove. — A  neat  and  compact  arrangement  for 
burning  mineral  oils,  as  a  substitute  for  gas,  in  small  cooking- 
stoves,  has  recently  been  adopted  in  the  United  States. 
Although  such  stoves  are  not  likely  to  come  into  use  in  this 
country  for  cooking  purposes,  they  might  be  found  convenient 
in  chemical  laboratories,  where  gas  is  not  readily  obtainable. 
The  base  of  the  stove  is  an  open-work  cast-iron  pediment, 
standing  on'three  feet,  and  holding  a  tin  can,  from  the  centre 
of  which  rises  a  wide  wick,  passing  through  a  drum,  which 


256  MISCELLANEOUS  CHEMICAL  PROCESSES 

serves  as  a  base  for  a  funnel-like  chimney.  The  case  of  this 
chimney  is  of  tin,  lined  throughout  with  fine  brass  gauze.  At 
the  bottom  the  chimney-case  has  openings  on  the  sides  for  the 
admission  of  atmospheric  air.  The  outer  cylinder  is  of  Russian 
sheet-iron,  and  is  surmounted  by  a  cast-iron  ring,  having 
upward  projecting  points  to  sustain  the  cooking  utensil.  These 
points  elevate  the  vessel  sufficiently  to  allow  the  heat  from  the 
flame  to  circulate  above  the  top  of  the  stove  around  the  sides 
of  the  kettle.  The  can  is  filled  with  naphtha,  benzine,  kerosene, 
or  petroleum,  the  chimney  removed,  and  the  wick  lighted. 
The  chimney  is  then  replaced,  and  the  stove  is  ready  for 
operation.  If  the  wick  is  kept  down  below  the  point  where 
the  flame  would  produce  illumination,  there  will  be  no  deposits 
of  carbon  on  the  vessel  used  for  cooking,  and  the  gauze,  with 
the  plentiful  supply  of  oxygen  through  the  chimney  apertures, 
will  yield  intense  heat. 

Sealing-Wax, — The  following  are  the  materials  and  pro- 
portions for  making  red  and  black  sealing-wax  : — 

For  black — 

Venice  turpentine ...         ...          ...         ...         ...  4^02. 

Shellac        ...          ...          ...          ...          9    oz. 

Colophony              ...          ...           ..          ...          ...  ^    oz. 

Lampblack  mixed  to  a  paste  with  oil  of  turpen- 
tine, a  sufficient  quantity. 
For  red — 

Venice  turpentine  ...         ...         , . .         ...         . . .  2    oz. 

Shellac        ...          ...          ...          ...          ...          ...  4    oz. 

Colophony              ...          ...          ...          ...          ...  i     oz. 

Chinese  Vermillion             ...          ...          ...          ...  i^  oz. 

Magnesia,  moistened  with  oil  of  turpentine       ...  I5  dr. 
For  the  best  red — 

Venice  turpentine ...         ...         ...  4    oz. 

Shellac        7    oz. 

Cinnabar    ...         ...         ...         ...         ...         ...  4    oz. 

Carbonate  of  magnesia  with  oil  of  turpentine  ...  ig  dr. 

Any  of  these  would  also  do  for  white  sealing-wax,  by  substi- 
tuting flake  white  for  the  lampblack,  vermillion,  and  cinnabar. 
Adding  a  small  quantity  of  fine  gum  benzoin  will  give  them  an 
agreeable  perfume. 

Lime  Water  is  made  by  adding  2  oz.  of  slaked  lime  to  i 
gallon  of  water,  and  shaking  it  well  for  a  few  minutes.  After 
twelve  hours  the  excess  of  lime  will  have  subsfded,  and  the 
lime  water  may  be  drawn  off  by  means  of  a  syphon  as  required. 


AND  COMPOSITIONS.  257 

Sugar,  Use  of  Lime  in  Extracting. — Peligot  long  ago  de- 
monstrated that,  owing  to  the  insoluble  nature  of  the  compound 
formed  of  lime  with  sugar,  the  former  substance  would  be  a 
most  valuable  agent  in  the  manufacture  of  the  latter.  Peligot's 
suggestion  is  now  being  carried  out  on  a  large  scale  in  MM. 
Schrotter  and  Wellman's  sugar-factory  at  Berlin.  The  molasses 
is  mixed  with  the  requisite  quantity  of  hydrate  of  lime  and 
alcohol  in  a  large  vat,  and  intimately  stirred  for  more  than 
half  an  hour.  The  lime  compound  of  sugar  which  separates 
is  then  strained  off,  pressed,  and  washed  with  spirit.  All  the 
alcohol  used  in  the  process  is  afterwards  recovered  by  distil- 
lation. The  mud-like  precipitate  thus  produced  is  mixed  with 
water,  and  decomposed  with  a  current  of  carbonic  acid,  which 
is  effected  in  somewhat  less  than  half  an  hour.  The  carbonate 
of  lime  is  removed  by  filtration,  and  the  clear  liquid,  contain- 
ing the  sugar,  evaporated,  decolourized  with  animal  charcoal, 
and  crystallized  in  the  usual  manner.  The  sugar  furnished  by 
this  method  has  a  very  clear  appearance,  and  is  perfectly  crys- 
talline. It  contains,  according  to  polarization  analysis,  66  per 
cent,  of  sugar,  12  per  cent,  of  water,  the  remainder  being 
uncrystallizable  organic  matter  and  salts.  The  yield,  of  course, 
varies  with  the  richness  and  degree  of  concentration  of  the  raw 
material ;  on  an  average,  30  lbs.  of  sugar  were  obtained  from 
100  lbs.  of  molasses. 

Prince  Rupert's  Drops. — The  properties  of  unannealed 
glass  are  beautifully  shown  in  these  scientific  toys.  They  are 
made  by  dropping  melted  glass  into  water,  which  takes  a  long 
oval  form,  tapering  to  a  point  at  one  end.  While  the  body  of 
these  drops  will  bear  a  smart  stroke  from  a  hammer  without 
fracturing,  if  a  portion  of  the  smaller  end  is  snapped  off,  the 
whole  mass  will  be  broken  into  an  almost  inpalpable  powder 
with  a  violent  shock.  Professor  Faraday  used  to  illustrate  the 
incompressibility  of  water  by  placing  one  of  these  drops  in  a 
phial  of  water,  the  concussion  from  the  disruption  of  the  drop 
shattering  the  glass  bottle.  Atiother  interesting  experime7it 
with  the  same  toy  is  this  : — In  place  of  water,  fill  the  phial 
with  melted  resin,  and  when  this  has  solidified,  nip  off  the  end 
of  the  glass  drop.  The  bottle  is  broken  as  before,  and  the 
mass  of  resin  is  deeply  fissured  throughout  its  length.  The 
drop  is  found  as  a  kernel,  loosely  aggregated   together,    but 

R 


258  MISCELLANEOUS  CHEMICAL  PROCESSES 

easily  detached  from  the  resin  entire.  When  broken  in  pieces, 
the  fragments  will  be  seen  to  have  the  form  of  a  cone  on  an 
hemispherical  base,  like  some  forms  of  hail. 

Printers'  Ink. — A  capital  ink  is  made  as  follows  : — Put 
linseed  oil  into  an  iron  pot  capable  of  holding  at  least  two  or 
three  times  the  quantity  introduced,  heat  it  over  a  fire  until  a 
dense  vapour  arises  from  it ;  then,  having  removed  the  pot 
from  the  fire,  apply  a  lighted  match,  attached  to  the  end  of  a 
stick,  to  the  surface  of  the  oil,  when  the  vapour  will  inflame  ; 
allow  it  to  burn  for  half-an-hour  or  more,  until  on  taking  out  a 
small  quantity  of  the  oil,  it  is  found  to  be  thick  and  tenacious  ; 
the  flame  is  then  to  be  extinguished  by  putting  a  cover  over  the 
pot,  and  keeping  tightly  covered.  To  6  quarts  of  oil,  thus 
prepared,  add  gradually  6  lbs.  of  black  resin,  and  dissolve 
it  by  the  aid  of  heat,  then  add,  in  small  quantities  at  a  time, 
1 1  lbs.  dry  yellow  soap,  cut  into  slices,  and  effect  the  combina- 
tion by  stirring  and  the  application  of  heat ;  this  is  the  varnish 
of  which  the  ink  is  to  be  made,  and  on  the  careful  preparation 
of  which  the  quality  of  the  ink  much  depends  ;  this  is  to  be 
mixed  with  i\  ounces  of  ground  indigo,  the  same  quantity  of 
ground  Prussian  blue,  4  lbs.  mineral  lampblack,  and  3^  lbs.  of 
the  best  vegetable  lampblack,  and  the  whole  ground  together 
into  a  perfectly  smooth  and  uniform  paste. 

Ink  of  different  colours  is  made  by  mixing  the  varnish  with 
various  dry  pigments,  such  as  vermilion,  redlead,  Indian  red, 
chrome  yellow,  chrome  red,  verdigris,  Prussian  blue,  &c.  &c. 
These  colours  are  ground  up  in  the  varnish  with  a  stone  and 
muller. 

In  the  above  process  there  is  considerable  danger  of  the  oil 
boiling  over  (which  would  be  a  serious  affair),  and  wherever  it 
is  practicable,  the  best  plan  is  to  buy  it  of  a  good  printing-ink 
manufacturer. 

To  Restore  Faded  Ink. — Ink  faded  from  age  may  be  revived 
by  damping  the  manuscript  with  very  weak  vinegar,  and  allow- 
ing it  to  remain  damp  for  an  hour  or  two.  Then  carefully 
wash  the  paper  over  with  a  solution  of  prussiate  of  potash. 
If  the  writing  does  not  appear  clear  at  once,  expose  the 
paper  to  the  air  for  a  few  hours,  keeping  the  whole  slightly 
damp. 


i 


AND  COMPOSITIONS,  259 

Inks. — Black  Ink. — Excellent  kind  of  writing  ink  may  be 
obtained  by  any  of  the  following  methods  : — 

1.  (Without  galls),  Logwood  chips  ^  lb.  ;  boil  in  three  pints 
of  water  down  to  2  pints,  strain  well,  and  let  it  cool ;  then  add 
2  5  grains  of  bichromate  of  potash.  Stir  well,  add  a  little  gum 
arabic  and  a  few  cloves. 

2.  (The  same  in  different  proportions.)  Take  i  lb.  of 
logwood  chips,  and  pour  on  a  pint  of  boiling  water  ;  let  it 
stand  until  all  the  colour  is  extracted  ;  then  strain  it,  and  add 
to  the  solution  about  a  thousandth-part  of  chromate  of  potash, 
or  sufficient  to  make  it  the  proper  colour.  This  mixture  does 
not  require  the  addition  of  gum  or  anything  else  to  give  it  con- 
sistency ;  it  will  corrode  steel  pens,  and  is  a  fine  permanent 
black. 

3.  Take  bruised  Aleppo  galls,  2  oz.  ;  green  copperas,  3  drs.  ; 
clean  rain-water,  i  quart ;  and  best  gum  arabic,  3  drs.  Mix 
in  a  bottle,  and  it  will  be  fit  for  use. 

4.  A  fine  Blue-black. — Take  bruised  Aleppo  galls,  5^  oz.; 
bruised  cloves,  \  oz.  ;  sulphate  of  iron,  \\  oz.;  sulphate  of  in- 
digo, in  the  form  of  a  slightly  acid  paste  (sulphindylate  of 
potash  ?),  i^  oz. ;  sulphuric  acid,  35  minims  ;  r^/^  rain-water, 
40  oz.  Macerate  the  galls  and  cloves  in  20  oz.  of  the  water 
for  a  week  ;  decant  the  liquor,  and  add  to  the  residue  of  the 
solid  ingredients  10  oz.  of  the  water,  with  which  continue  the 
maceration  for  four  days  ;  then  decant  as  before,  and  repeat 
the  maceration  with  the  remaining  10  oz.  of  water  for  another 
period  of  four  days.  Mix  now  the  whole  of  the  liquors,  re- 
covering from  the  galls  all  that  can  be  obtained  by  squeezing 
them  in  a  cloth,  and  afterwards  filter.  To  this  add  first  the 
sulphate  of  iron,  then  the  sulphuric  acid,  and  lastly  the  indigo 
paste.  Care  must  be  taken  that  the  indigo  does  not  contain 
much  free  acid.      This  is  also  a  good  copying  ink. 

Indestructible  Ink  for  resisting  the  action  of  corrosive  sub- 
stances :  Twenty-five  grains  of  copal  in  powder  are  to  be  dis- 
solved in  two  hundred  grains  of  oil  of  lavender,  by  the  assistance 
of  a  gentle  heat,  and  are  then  to  be  mixed  with  two  and  a 
half  grains  of  lampblack,  and  a  half  grain  of  indigo. 

6.  Copying  Inks. —  i.  Three  parts  by  weight  of  white  gly- 
cerine ;  three  parts  of  purified  white  honey,  best  quality  ;  i  o 
parts  of  violet,  black,  or  other  coloured  ink.  Mix  up  well,  and 
leave  the  mixture  to  settle  two  or  three  days  before  using,      2. 


26o  MISCELLANEOUS  CHEMICAL  PROCESSES 

Four  parts  by  weight  of  white  glycerine  ;  four  parts  of  purified 
white  honey,  best  quaUty  ;  ten  parts  of  Robertson's  ink  ;  a  half 
part  of  powdered  gum  arable.  Add  one  or  two  drops  of  strong 
solution  of  bichloride  of  mercury  to  prevent  deterioration  of  the 
ink  ;  stir  up  well,  and  leave  it  to  settle  for  two  or  three  days 
before  using.  If  it  should  be  found,  in  taking  copies  from  ink 
according  to  recipe  No.  i,  that  thicker  characters  are  produced 
than  those  of  the  original,  the  proportions  of  glycerine  and 
honey  may  be  respectively  reduced  to  two  parts  of  each,  or 
another  quarter  by  weight  of  one  part  powdered  gum  arabic 
may  be  added. 

Indelible  hik. — i,  A  very  good  mdelible  black  ink,  capable 
of  resisting  chlorine,  oxalic  acid,  and  ablution  with  a  hair  pen- 
cil or  sponge,  may  be  made  by  mixing  some  of  the  ink  made 
by  the  preceding  prescription,  with  a  little  genuine  China  ink. 
It  writes  well.  Many  other  formulae  have  been  given  for  in- 
delible inks,  but  they  are  all  inferior  in  simplicity  and  useful- 
ness to  the  one  now  prescribed. 

Solution  of  nitrate  of  silver  thickened  with  gum,  and  written 
with  upon  linen  or  cotton  cloth,  previously  imbued  with  a  solu- 
tion of  soda,  and  dried,  is  the  ordinary  permanent  ink  of  the 
shops.  Before  the  cloths  are  washed,  the  writing  should  be 
exposed  to  the  sunbeam,  or  to  bright  daylight,  which  blackens 
and  fixes  the  oxide  of  silver.  It  is  easily  discharged  by  chlo- 
rine and  ammonia.  2.  A  good  permanent  ink  may  be  made 
by  mixing  a  strong  solution  of  chloride  of  platinum  with  a  little 
potash  sugar,  and  gum  to  thicken.  The  writing  made  there- 
with should  be  passed  over  with  a  hot  smoothing-iron  to  fix  it. 
3.  Nitrate  of  silver,  i  to  2  drs.  ;  water,  \  oz.  ;  dissolve,  add  as 
much  of  the  strongest  ammonia-water  as  will  dissolve  the  pre- 
cipitate formed  on  its  first  addition,  then  further  add  mucilage 
I  or  2  drs.,  and  a  little  sap  green  to  colour.  Writing  executed 
with  this  ink  turns  black  on  being  passed  over  a  hot  Italian 
iron.  4.  Asphaltum,  i  part ;  oil  of  turpentine,  4  parts  ;  dis- 
solve, and  colour  with  printers'  ink.  Very  permanent.  5.  20 
grains  of  sugar  dissolved  in  30  grains  of  water,  and  the  ad- 
dition to  the  solution  of  a  few  drops  of  concentrated  sulphuric 
acid  ;  the  mixture  is  then  heated,  when  the  sugar  is  carbonized 
by  the  action  of  the  acid.  It  is  said  that  the  writing  is  not 
only  of  a  solid  black  colour,  but  that  the  acid  resists  the  action 
of  chemical  agents. 


AND  COMPOSITIONS.  261 

Permanent  Ink  for  Writing  in  Relief  on  Zinc. — Bichloride 
of  platinum,  dry,  one  part ;  gum  arable,  one  part  ;  distilled 
water,  ten  parts.  The  letters  traced  upon  zinc  with  this  solu- 
tion turn  black  immediately.  The  black  characters  resist  the 
action  of  weak  acids,  of  rain,  or  of  the  elements  in  general,  and 
the  liquid  is  thus  adapted  for  making  signs,  labels,  or  tags 
which  are  liable  to  exposure.  To  bring  out  the  letters  in  relief, 
immerse  the  zinc  tag  in  a  weak  acid  for  a  few  moments.  The 
writing  is  not  attacked,  while  the  metal  is  dissolved  away. 

Blacking. — Liquid  Blacking.  —  i.  Boil  i  oz.  each  of  powdered 
galls,  starch,  and  copperas,  and  2  oz.  of  white  Castile  soap, 
with  2  quarts  of  water  ;  then  strain  and  mix  with  3  oz.  of  fine 
ivory-black  and  6  oz.  of  molasses.  2.  Ivory  or  bone  black,  2  lbs. ; 
neat's-foot  oil,  4  oz.  ;  mix,  and  add  3  quarts  of  sour  beer  or 
vinegar,  and  a  spoonful  of  any  kind  of  spirit  \  stjr  till  smooth, 
add  2  oz.  of  oil  of  vitriol,  and  sprinkle  on  it  ^  dr.  powdered 
resin.  Then  boil  together  3  pints  of  sour  ale  with  a  little  log- 
wood, and  \  ounce  of  Prussian  blue,  3  oz.  of  honey,  and  8  oz. 
of  treacle;  mix,,  but  do  not  bottle  for  two  or  three  days.  3. 
Ivory  or  bone  black,  8  oz.  ;  brown  sugar  or  treacle,  8  oz.  ; 
sweet  oil,  i  oz.  ;  oil  of  vitriol,  \  oz.  ;  vinegar,  2  quarts  ;  mix 
the  oil  with  the  treacle,  then  add  the  oil  of  vitriol  and  vinegar, 
and  lastly  the  black. 

Paste  Blackijig. — Powdered  bone-black  is  mixed  with  half 
its  weight  of  molasses,  and  one-eighth  of  its  weight  of  olive  oil, 
and  to  this  is  afterwards  added  one-eighth  of  its  weight  of 
hydrochloric  acid,  and  one-fourth  of  its  weight  of  strong  sul- 
phuric acid.  The  whole  is  to  be  then  mixed  up  with  water 
into  an  unctuous  paste. 

Blacking  for  Harness. — Take  4  oz.  of  black  resin,  and  put  it 
in  a  glazed  pipkin  over  a  slow  fire  ;  when  melted,  add  6  oz.  of 
beeswax.  When  the  beeswax  is  melted,  take  it  off  the  fire, 
and  add  i  dr.  of  Prussian  blue  in  powder  and  i  oz.  of  lamp- 
black ;  stir  till  perfectly  mixed,  and  add  turpentine  until  it  be- 
comes a  thin  paste,  then  let  it  cool.  When  required  to  be  used, 
rub  it  over  the  harness,  and  polish  with  a  soft  brush. 

Piecing  Indiarubber. — Make  a  long  bevel  on  the  ends  you 
wish  to  join  (with  a  sharp,  rough-edged  knife  and  water),  scrape 
the  bevels  rough  with  the  edge  of  the  knife,  and  when  quite 
dry,  give  each  a  coat   of  indiarubber  solution — sav   i   oz.   of 


262  LIGHTING. 


rubber,  not  vulcanized,  to  5  oz.  of  turpentine.  When  the  first 
coat  is  dry,  give  it  another  ;  and  when  that  is  dry,  he  may  put 
the  two  ends  together.  It  is  impossible  to  make  a  firmer  joint 
than  by  this  method. 

Vulcanized  Indiarubber. — It  is  impossible  to  manufacture 
vulcanized  indiarubber  that  shall  be  free  from  odour,  and  not 
liable  to  become  rotten.  With  regard  to  smell,  a  good  deal 
can  be  done  towards  making  it  agreeable  by  exposure  to  the 
atmosphere,  and  by  desulphurization  ;  but  the  best  plan  is  to 
scent  it  in  the  manufacture,  and  so  disguise  the  natural  smell. 
With  regard  to  rubber  becoming  rotten  or  decomposing,  it  is  a 
question  of  manufacture  and  exposure  to  the  sun's  rays,  which 
is  the  most  powerful  agent  in  effecting  the  decomposition.  The 
red  rubber  is  as  liable  to  become  rotten  as  any  other  of  the 
same  specific,  gravity.  It  also  has  the  ordinary  odour  of  vul- 
canized indiarubber,  unless  artificially  scented. 

Bones  for  Manure,  Preparation  of. — Illienkof,  a  Russian 
chemist,  gives  the  following  process,  which,  it  is  said,  has 
received  the  approbation  of  Liebig  : — The  author  mixes  4000 
kilos,  of  ground  bones  with  4000  kilos,  of  wood  ashes  contain- 
ing I  o  per  cent,  of  carbonate  of  potash,  and  adds  600  kilos,  of 
quicklime.  This  mixture  he  places  in  a  tank  or  fosse  with 
water  sufficient  to  make  the  whole  moist.  In  a  short  time  the 
bony  matter  is  completely  disaggregated  by  the  caustic  potash, 
and  the  pasty  mass  formed  is  then  taken  from  the  tank,  dried, 
mixed  with  an  equal  weight  of  mould,  and  is  then  ready  to  be 
distributed. 

Chimney  Lamp. —  Some  chimneys  will  last  for  months, 
w^hile  others,  apparently  as  sound  and  good,  will  break  after  a 
short  use,  without  any  apparent  cause.  The  great  cause  of 
their  being  brittle  and  breaking  so  easily  lies  in  the  material 
they  are  made  from.  There  is  "  shoddy  "  in  glass  as  well  as 
in  cloth.  A  great  many  manufacturers  make  chimneys  from 
silicate  of  lime  instead  of  silicate  of  lead.  The  glass  made 
from  the  silicate  of  lime  has  about  the  following  proportions  : — 
Sand,  100  ;  soda,  45  ;  lime,  20  to  25  ;  nitre,  7  to  10.  Lime 
being  a  non-conductor  of  heat,  the  chimney  will  not  bear  the 
expansion  caused  by  the  heat ;  and  if,  by  gradual  heating,  the 
chimney  does  not   break  on   the  lamp,  a  few  times   heating 


LIGHTING. 


263 


makes  it  so  brittle  that  it  breaks  with  the  l.east  effort  at  cleaning 
it,  no  matter  how  much  care  is  used.  The  silicate  of  lead  has 
about  the  following  proportions: — Sand,  100;  lead,  40  to  50; 
soda,  20  to  25  ;  nitre,  10  to  15.  Lead  being  very  ductile,  and 
a  good  conductor  of  heat,  a  chimney  made  from  this  formula 
will  almost  melt  before  it  will  crack  with  the  heat.  The 
uninitiated  may  tell  the  difference  of  the  chimneys  made  of 
these  different  qualities  of  glass  by  ringing  them  ;  the  vibration 
from  the  lead  glass  chimney  has  a  sweet,  bell-like  sound,  whilst 
the  lime  glass  has  a  short,  harsh  sound.  The  difference  of  the 
cost  of  manufacture  is  only,  in  material,  about  8d.  per  dozen. 
Another  point  is  in  annealing  ;  chimneys  as  a  general  rule  are 
not  annealed  ;  under  a  powerful  microscope  the  difference  can 
be  seen  in  the  glass ;  the  particles  in  the  annealed  glass  lie  close 
and  compact,  while  the  unannealed  seem  ready  to  diverge. 


Glass  Chimneys,  Why  they  Break. — The  shattering  of  gas 
chimneys  is  caused  by  sudden  and  excessive  change  of  tempera- 
ture. If,  on  extinguishing  the  light,  the  chimneys  are  allowed 
.  to  cool  slowly,  the  spontaneous  shattering  complained  of  will 
not  occur.  A  slit  made  by  a  diamond  along  the  whole  length 
of  the  chimney  will 
often  save  the  glass 
from  such  rupture. 
If  the  glasses  were, 
on  being  taken  down, 
embedded,  while  still 
hot,  in  hot  ashes  or 
other  such  material, 
and  thus  left  to  cool 
slowly,  less  breakage 
would  occur. 

Hydrogen  Lamp. 

— The  following  pro- 
duces a  flame  with 
good  heat,  but  not 
good  light.  G  is  a 
glass  or  earthenware 

vessel,  with  air-tight  brass  top,  in  which  is  screwed  the  valve 
V  ;   and  T  the  tube  which  contains  the  piece  of  spongy  platina 


264 


LIGHTING. 


S  ;  Z  is  a  ball  of  zinc,  suspended  in  the  inner  vessel  I  ;  H  is 
a  hole  to  permit  the  air  to  pass  to  and  fro  ;  and  D,  dilute 
sulphuric  acid  ;  p  and  p  show  the  relative  positions  of  the  same 
in  the  two  vessels  G  and  I,  when  the  valve  is  closed.  The  dilute 
acid  acting  on  the  zinc  gives  off  hydrogen,  which,  having  no 
way  to  escape,  forces  the  liquid  into  the  outer  vessel,  and  so 
prevents  any  further  chemical  action  until  the  valve  is  opened, 
when  the  pressure  of  the  atmosphere  forces  the  acid  to  attain 
an  equal  level  in  both  vessels,  and  so  forces  the  hydrogen  out 
at  the  nozzle  and  through  the  tube,  causing  the  platina  to 
become  red  hot  and  isnite  the  gas. 


The  "A  B  C "  Gas  Meter. — This  meter  has  attached  to  it 
an  index  which  performs  at  once  the  double  duty  of  giving  the 
consumption  of  gas  and  the  price  thereof.      In  the  sketch  is 


<^  PATENT  ^e^^ 


AMOUNT  PAYABLE  FOR  GAS   AT  5/ 


CUBIC 


FEET 


shown  the  patent  index  :  5250  ft.  are  supposed  to  have  been 
consumed,  and  the  money  payable  at  the  assumed  price  of  5s. 
per  1000  ft.  is  ^i,  6s.  3d.,  as  indicated.  As  i6|  ft.  from 
the  3d.  gradually  changes  to  4d.,  and  so  on  for  every  i6|  ft. 
consumed,  till  the  quantity  amounts  to  5400  ft.,  when  "7" 
appears  under  the  shillings'  heading  and  '•'  o  "  under  the  pence, 


DYES.  265 

the  total  being  ^i,  7s.,  and  so  on  for  any  larger  quantity. 
This  index  should  prevent  all  disputes  as  to  cost.  It  is  intended 
that  the  registration  should  be  continuous,  but  that  the  cash 
index  should,  upon  each  quarterly  taking  of  the  state  of  the 
meter,  be  put  back  to  zero,  and  a  ticket  of  the  cash,  as  well  as 
the  number  of  feet  to  be  charged,  to  be  left  with  the  consumer ; 
the  one  will  be  a  check  on  the  other.  When  the  price  of  gas 
is  changed,  the  index  can  be  altered  at  a  trifling  charge,  and 
old  meters  may  have  the  cash  index  added  for  about  a  crown. 
The  manufactory  is  at  the  Meter  Company's  Works,  Johnson's 
Place,  Lupus  Street,  Pimlico. 

Water  in  Gas-Pipes. — Where  the  pipes  have  been  properly 
laid  (that  is,  inclining  every  way  to  the  meter)  it  is  impossible 
for  the  water  to  remain  in  gas-pipes.  But  it  is  possible  that 
the  water  may  have  condensed  in  the  pipes  in  sufficient  quan- 
tity to  run  back  into  the  meter,  and  raise  the  water  in  it  above 
the  proper  level  ;  in  that  case  the  lights  would  certainly  go  out. 
The  remedy  is  to  unscrew  the  plug  of  the  meter,  and  let  the 
surplus  water  run  out. 

Removal  of  Bisulphide  of  Carbon  from  Coal  Gas. — This 
substance  imparts  a  very  disagreeable  odour  to  gas,  and  the 
sulphur  it  contains  is,  during  combustion,  changed  into  sul- 
phurous acid,  which  is  injurious  to  animal  life,  destroys  vege- 
table colours,  &c.  The  bisulphide  is  a  highly  volatile  liquid, 
and  its  entire  removal  from  gas  has  been  hitherto  extremely 
difficult,  if  not  impossible.  Mr  Lewis  Thomson,  however,  has 
found  that  it  may  be  entirely  got  rid  of  by  passing  the  gas, 
after  it  has  left  the  hydraulic  main,  and  before  it  enters  the 
condenser,  along  with  a  certain  quantity  of  steam,  through  a 
tube  or  retort  of  cast  iron,  heated  to  about  1200°  Fahr. 
The  vapour  of  water  and  the  bisulphide  then  mutually  decom- 
pose each  other,  sulphuretted  hydrogen  and  carbonic  acid 
being  formed.      Both  these  are  removed  in  the  usual  way. 

Royal  Blue  Dye  for  Silk. — Into  a  tub  partly  filled  with 
cold  water  pour  2  pints  of  nitrate  of  iron  ;  then  take  i  pint  of 
water  and  |-  pint  of  muriatic  acid  ;  to  this  add  3  oz.  of  crys- 
tals of  tin  ;  when  dissolved,  pour  it  into  the  vessel  containing 
the  iron  solution,  stir  well,  throw  in  the  silk,  and  work  for  some 
time.      In    another  tub   dissolve  8  oz.  of  yellow  prussiate  of 


266  D  YES. 


potash,  and  add  to  it  2  oz.  (by  measure)  of  vitriol ;  the  silk  is 
wrung  out  dry  from  the  iron  solution  and  put  directly  into  the 
prussiate  solution,  in  which  it  is  worked  for  some  time.  It  is 
then  washed  in  cold  water  with  2  oz.  of  alum  dissolved  in  it.  If 
the  dye  is  not  dark  enough,  instead  of  being  washed  in  the 
alum- water,  the  silk  may  be  put  into  the  iron  again  and  through 
the  prussiate  in  the  same  way,  and  worked  for  about  the  same 
time  as  before,  but  add  a  little  more  prussiate.  Deeper  shades 
are  obtained  by  using  more  iron  and  tin,  or  by  giving  several 
dips.  The  silk  must  be  perfectly  freed  from  grease  before  com- 
mencing the  dyeing  operation.  The  mixture  above  recom- 
mended will  dye  5  lbs.  weight  of  silk. 

Dyes  for  Woollens. — For  60  lbs.  of  woollen  yarn  take  2  lbs. 
of  flavine,  6  lbs.  of  alum,  i  lb.  of  tin  crystals.  Dissolve  in  boil- 
ing water.  Then  dissolve  separately  4  oz.  of  red  prussiate  of 
potash,  and  add  it  to  the  above.  Then  add  ^\  lbs.  extract 
of  indigo  and  12  oz.  oxalic  acid.  Dye  in  the  usual  manner. 
This  makes  a  full  green.  For  deep  scarlet  take  3^  gallons  of 
cochineal  liquor,  containing  i|  lbs.  of  cochineal  per  gallon,  36 
oz.  of  starch.  Boil,  and  add  |-  pint  of  mixed  berry  and  fustic 
liquor  at  is'',  i  lb.  bin-oxalate  of  potash,  3  oz.  of  crystals  of  tin, 
and  12  oz.  of  bichloride  of  tin  at  100°. 

For  Black  Silk  and  Wool. — Silk  to  be  dyed  black  must  be 
first  washed  free  from  grease,  and  then  gently  boiled  for  half 
an  hour  in  a  dilute  solution  of  nitrate  of  iron.  Take  out  and 
rinse  in  cold  water,  and  then  boil  with  logwood  of  half  the 
weight  of  the  silk  itself  for  one  hour.  To  dye  wool  black,  boil 
it  with  its  own  weight  of  logwood  for  an  hour,  and  then  add 
sulphate  of  iron  in  the  proportion  of  about  one  pound  to  every 
thirty  of  wool. 

For  Ostrich  Feathers,  &c. — For  ostrich  feather  dyeing, 
first  expose  them  to  sulphur-vapour  to  bleach  them,  then  dye. 
Black. — Immerse  for  two  or  three  days  in  a  bath  (hot  at  first), 
of  logwood  eight  parts  and  copperas  or  acetate  of  iron  about 
one  part.  Blue. — The  indigo  vat.  Brown. — Any  brown  dyes 
for  silk  or  wool.  Crz?nson. — A  mordant  of  alum  followed  by  a 
hot  bath  of  Brazil  wood  and  a  weak  one  of  cudbear.  Pink  or 
Rose. — Safflower  and  lemon  juice.  Plum. — Red  dye  followed 
by  an  akaline  bath.      Red. — Alum  mordant  and  a  hot  Brazil- 


I 


DYES.  267 

wood  bath.      Yellow. — Alum  mordant  turmeric  bath.      Other 
shades  by  mixtures. 

Aniline  Dyes. — The  colouring-matters  produced  from  ani- 
line and  analogous  matters  are  all,  with  the  exception  of  the 
Fuchsine  and  Perkins's  violet,  insoluble  in  water,  and  many- 
attempts  have  been  made  to  substitute  a  less  costly  solvent  for 
the  alcohol  hitherto  employed.  M.  Gaultier  de  Claubry,  a 
French  chemist,  has  recently  taken  out  a  patent  for  a  method 
of  accomplishing  this.  He  says  that  a  great  number  of  sub- 
stances, such  as  gum,  mucilage,  almond,  and  other  soap,  glu- 
cose, dextrine,  the  gelatinous  portion  of  various  feculas,  of 
lichens,  and  of  fuci,  render  water  a  solvent  of  such  colouring- 
matter,  but  that  the  best  and  most  economical  results  are  to  be 
obtained  by  means  of  decoctions  of  the  bark  known  as  Panama 
{Quillaia  sapotiarid),  or  of  the  root  of  the  Egyptian  soap-plant 
{Gypsophila  strutiuiii).  The  Saponaria  officinalis,  he  adds, 
may  be  employed,  but  is  less  energetic  in  its  action  than  the 
other  two.  The  solutions  are  obtained  by  pouring  the  boiling 
liquors  upon  the  colouring-matter  in  powder,  agitating,  decant- 
ing, and,  if  the  solution  be  not  complete,  repeating  the  process. 
The  solutions  thus  obtained  may  be  reduced  to  extracts  by 
evaporation,  but  continued  ebullition,  especially  if  the  water 
contain  sulphate  or  carbonate  of  lime,  may  injure  the  colours. 
A  better  method,  according  to  M.  Gaultier  de  Claubry,  is  to 
triturate  the  powdered  colouring-matter  with  the  extract  of 
Gypsophila  slrutiu77t,  and  then  afterwards  to  add  water  by  de- 
grees ;  but  as  the  reds  dissolve  more  readily  than  the  blues,  it 
is  necessary  afterwards  to  mix  all  the  products  together.  The 
solutions  obtained  by  means  of  the  extracts  above-named  are 
said  to  work  readily  with  gum,  dextrine,  and  albumen,  sepa- 
rately or  combined.  The  advantages  claimed  for  the  process 
by  the  patentee  are  economy,  perfect  unity  of  tints,  which  will 
not  soil  linen  by  contact,  and  suppression  of  inconvenience 
caused  to  the  dyers  by  the  use  of  alcohol  or  wood-spirit.  In 
connection  with  the  latter,  it  should  be  mentioned  that  the  at- 
tempt to  substitute  it  for  alcohol  has  been  defeated  by  the 
workmen,  who  have,  in  many  instances,  refused  to  use  it  on 
account  of  its  effect  on  their  health. 

To  Colour  Straw  Black. — The  quantities  are  intended  for 
twenty-five  hats  or  bonnets.      The  articles   are  kept  for  two 


268  WA  TERPR  00  RING. 


hours  in  a  boiling  decoction  of  4  lbs.  of  logwood,  i  lb.  of  su- 
mach, and  of  5  oz.  of  fustic  ;  afterwards  they  are  dipped  into  a 
solution  of  nitrate  of  iron,  then  well  rinsed  with  water,  and 
when  dry,  are  painted  over  with  a  solution  of  gum  or  dextrine. 
The  iron  liquor,  as  well  as  the  other  ingredients,  are  kept  by 
all  dealers  in  dye-stuffs. 

Printed  Cottons,  to  Wash. — Infuse  three  gills  of  salt  in 
four  quarts  of  water ;  put  the  cotton  goods  in  while  hot,  and 
leave  till  cold,  and  in  this  way  the  colours  are  rendered  perma- 
nent, and  will  not  fade  by  subsequent  washing. 

bleaching- Powder. — When  hydrate  of  lime,  very  slightly 
moist,  is  exposed  to  chlorine  gas,  the  latter  is  eagerly  absorbed, 
and  a  compound  produced  which  has  attracted  a  great  deal  of 
attention ;  this  is  the  bleaching-powder  of  commerce,  now 
manufactured  on  an  immense  scale,  for  bleaching  linen  and 
cotton  goods.  It  is  requisite  in  preparing  this  substance,  to 
avoid  with  the  greatest  care  all  elevation  of  temperature,  which 
may  be  easily  done  by  slowly  supplying  the  chlorine  in  the  first 
instance.  The  product,  when  freshly  and  well  prepared,  is  a 
soft,  white  powder,  which  attracts  moisture  from  the  air,  and 
exhales  an  odour  sensibly  different  from  that  of  chlorine.  It  is 
soluble  in  about  ten  parts  of  water  ;  the  unaltered  hydrate  being 
left  behind,  the  solution  is  highly  alkaline,  and  bleaches  feebly. 
When  hydrate  of  lime  is  suspended  in  cold  water,  and  chlorine 
gas  transmitted  through  the  mixture,  the  lime  is  gradually  dis- 
solved, and  the  same  peculiar  bleaching  compound  produced. 

Waterproofing  with  Paraffin. — The  materials  which  in 
modern  times  were  first  employed  for  waterproofing  were  bees- 
wax and  the  various  kinds  of  drying  oil,  especially  linseed  oil, 
which  were  rendered  more  siccative  by  boiling  or  some  other 
of  the  processes  usually  employed  for  that  purpose.  About 
forty  years  ago  caoutchouc  was  first  successfully  used,  for  ren- 
dering fabrics  and  other  materials  waterproof,  by  the  late  Mr 
Charles  Macintosh  ;  and  after  an  interval  of  about  twenty 
years,  gutta-percha  was  first  imported  into  this  country,  and 
immediately  applied  for  similar  purposes.  In  1832  paraffin 
was  discovered  by  Reichenbach  in  the  course  of  his  admirable 
researches  on  wood  and  coal  tars  ;  he,  however,  only  succeeded 
in  obtaining  it  in  very  small  quantity,  so  that  for  a  long  time 


WATERPROOFING.  269 

it  was  only  known  as  a  chemical  curiosity.  It  is  to  Mr  James 
Young  that  we  are  indebted  for  the  production  of  this  material 
on  an  industrial  scale,  by  his  process  which  he  patented  nearly 
fifteen  years  ago. 

A  few  years  ago  a  patent  was  taken  out  by  Dr  Stenhouse  for 
employing  paraffin  as  a  means  of  rendering  leather  waterproof, 
as  well  as  the  various  textile  and  felted  fabrics  ;  and  since  then 
additional  patents  have  been  granted  for  an  extension  of,  and 
improvement  on  the  previous  one,  which  consisted  chiefly  in 
combining  the  paraffin  with  various  proportions  of  drying  oil, 
it  having  been  found  that  paraffin  alone,  especially  when 
applied  to  fabrics,  became  to  a  considerable  extent  detached 
from  the  fibre  of  the  cloth  after  a  short  time,  owing  to  its  great 
tendency  to  crystallize.  The  presence,  however,  of  even  a 
small  quantity  of  drying  oil  causes  the  paraffin  to  adhere  much 
more  firmly  to  the  texture  of  the  cloth,  from  the  oil  gradually 
becoming  converted  into  a  tenacious  resin  by  absorption  of 
oxygen. 

In  the  application  of  paraffin  for  waterproofing  purposes,  it 
is  first  melted  together  with  the  requisite  quantity  of  drying 
oil,  and  cast  into  blocks.  The  composition  can  then  be  applied 
to  fabrics  by  rubbing  them  over  with  a  block  of  it,  either  cold 
or  gently  warmed,  or  the  mixture  may  be  melted  and  laid  on 
with  a  brush,  the  complete  impregnation  being  effected  by  sub- 
sequently passing  it  between  hot  rollers.  When  this  paraffin 
mixture  has  been  applied  to  cloth  such  as  that  employed  for 
blinds  or  tents,  it  renders  it  very  repellent  to  water,  although 
still  pervious  to  air. 

Cloth  paraffined  in  this  manner  forms  an  excellent  basis  for 
such  articles  as  capes,  tarpaulins,  &c.,  which  require  to  be 
rendered  quite  impervious  by  subsequently  coating  them  with 
drying  oil — the  paraffin  in  a  great  measure  preventing  the  well- 
known  injurious  influence  of  dr)-ing  oil  on  the  fibre  of  the  cloth. 
The  paraffin  mixture  can  also  be  very  advantageously  applied 
to  the  various  kinds  of  leather.  One  of  the  most  convenient 
ways  of  effecting  this  is  to  coat  the  skins  or  manufactured 
articles,  such  as  boots,  shoes,  harness,  pump-buckets,  &c.,  with 
the  melted  composition,  and  then  to  gently  heat  the  articles 
until  it  is  entirely  absorbed.  When  leather  is  impregnated 
with  the  mixture,  it  is  not  only  rendered  perfectly  waterproof, 
but  also  stronger  and  more  durable.      The  beneficial  eff"ects  of 


270 


GILDING  AND  BRONZING. 


this  process  are  peculiarly  observable  in  the  case  of  boots  and 
shoes,  which  it  renders  very  firm  without  destroying  their  elas- 
ticity. It  therefore  not  only  makes  them  exceedingly  durable, 
but  possesses  an  advantage  over  ordinary  dubbing  in  not  inter- 
fering with  the  pohsh  of  these  articles,  which,  on  the  whole,  it 
rather  improves.  The  superiority  of  paraffin  over  most  other 
materials  for  some  kinds  of  waterproofing  consists  in  its  com- 
parative cheapness,  in  being  easily  applied,  and  in  not  materially 
altering  the  colour  of  fabrics,  which  in  the  case  of  light  shades 
and  white  cloth  is  of  very  considerable  importance. 

Waterproofing  for  Rick  Cloths. — Plunge  the  fabric  into  a 
solution  containing  20  per  cent,  of  soap,  and  afterwards  into 
another  solution  containing  the  same  percentage  of  sulphate  of 
copper  ;  wash  the  fabric,  and  the  operation  is  finished.  An 
indissoluble  stearate,  margarate  or  oleate  of  copper,  is  formed 
in  the  interstices  of  the  tissue,  which  thus  becomes  impervious 
to  moisture.  This  process  is  particularly  recommended  for 
rick  cloths,  awnings,  &c. 

Waterproofing  Cotton  Fabrics. —  If  for  black  work,  mix 
enough  lampblack  and  boiled  oil  to  cover  the  whole  surface ; 
if  yellow,  use  yellow  ochre  ;  add  about  \  lb.  of  driers  for  each 
gallon  of  oil.  Give  the  cloth  two  or  three  coats  of  the  above  ; 
and  if,  after  the  last  coat  is  dry,  it  should  remain  sticky,  give  it 
a  coat  of  the  following  mixture  : — Boil  2  lbs.  of  shellac  in  4 
quarts  of  water,  and  add  a  little  ammonia  ;  when  cold,  add 
lampblack  or  yellow  ochre  as  required. 

Textile  Fabrics,  to  Render  Fireproof. — A  very  excellent 
method  of  rendering  textile  fabrics  fireproof  without  injuring 
their  colour,  whatever  it  may  be,  consists  in  dipping  them  in  a 
solution  containing  35  per  cent,  gum,  35  per  cent,  starch,  and 
30  per  cent,  of  the  compound  which  is  obtained  by  dissolving 
superphosphate  of  lime,  decomposing  the  salt  by  excess  of  am- 
monia, filtering,  purifying  with  animal  charcoal,  concentrating 
by  evaporation,  decomposing  with  5  per  cent,  silex,  evaporating 
to  a  crystalline  mass,  and  then  drying  and  pulverizing. 

Electrotyping, — Wash  article  or  mould  over  with  a  solution 
of  acetate  of  copper,  or  nitrate  of  silver  in  alcohol,  and  then, 
without  allowing  it  to  dry,  expose  to  the  action  of  sulphuretted 
hydrogen  gas.      A  sulphuret  is  formed  which  is  an  excellent 


GILDING  AND  BRONZING.  271 

conductor  of  electricity  ;  and,  when  dry,  may  be  put  into  the 
copper  bath.  Minute  animals  and  delicate  objects  may  be 
readily  coated  in  this  way. 

To  prepare  the  gold  solutioft,  make  a  saturated  solution  of 
cyanide  of  potassium  as  before,  and  pour  off  this  solution  upon 
the  contents  of  a  1 5 -grain  bottle  of  chloride  of  gold  until  the 
latter  is  quite  dissolved  ;  then  dilute  with  water  in  the  same 
ratio  as  in  the  silver  electrolyte — that  is,  one  part  of  the  solution 
of  chloride  of  gold  in  cyanide  of  potassium,  with  three  parts  of 
water.     This  solution  filtered  forms  the  gold  electrolyte. 

Mounting  the  battejy  for  plating  or  gilding  is  the  next  opera- 
tion.     If  the  article  or  articles  to  be  plated  or  gilt  are  small,  a 
single  element  will,  in  all  probability,  be  sufficient  to  produce 
the  requisite  amount  of  electric  current.      Place  the  zinc  in  the 
middle  of  the  tumbler,  then  insert  the  earthenware  cell  in  the 
zinc,  and  holding  it  down  with  the  left  hand,  pour  into  the 
tumbler  dilute  sulphuric  acid  until  it  reaches  to  the  upper  rim  of 
the  cell.     The  cell  itself  is  next  filled  with  concentrated  nitric 
acid.      The  plate  or  strip  of  platinum  is  finally  inserted  in  the 
nitric  acid.      The  zincs  are  generally  amalgamated  when  you 
buy  them  ;   if  this  operation  has  been  omitted,  you  can  do  it 
yourself  by  rubbing  over  the  moistened  surfaces  a  cloth  dipped 
in  nitrate  of  mercury.      Place  one  connecting-wire  in  the  zinc 
binding- screw,  and  the  other  in  the  platinum  binding-screw. 
The  zinc  wire  is  the  negative  pole,  and  is  frequently  called  the 
"  zincoid  ;"  whilst  the  platinum  wire  is  the  positive  pole,  and 
is  denominated  the  "  platinoid."     At  the  end  of  the  negative 
wire  the  object  to  receive  the  deposit  is  placed  by  suspension 
on  a  hook,  or  otherwise,  in  metalhc  contact,  and  then  immersed 
in  the  electrolyte.      On  the  end  of  the  positive  wire  either  the 
piece  of  silver  or  of  gold  is  fixed  ;   if  the  electrolyte  be  silver, 
the  silver  plate  is  attracted,  and  the  gold  plate  in  the  other 
case.     The  silver  and  the  gold  coin  can  be  beaten  out  into 
thin  plates  for  the  purpose,  and  then  soldered  to  their  respec- 
tive wires,  or  attached  by  drilling  holes  and  then  suspending 
each  on  a  hook.      The  objects  to  be  gilt  or  plated  must  be 
thoroughly  cleaned  of  all  impurities,  by  means  of  a  brush  and 
rouge  (sesqui-oxide  of  iron) ;   and  they  must  then  be  dipped  in 
a  solution  of  salts  of  tartar  to  remove  grease,  and  finally  washed 
in  water.      So  prepared,  they  are  suspended  on  the  negative 
hook   and   immersed   in  the   electrolyte.      The  plate   on   the 


272  GILDING  AND  BRONZING. 

positive  hook  is  likewise  immersed  in  the  same  solution,  and 
brought  near  to  the  object,  but  on  no  account  in  contact  with  it. 
The  electric  current  now  circulates,  because  the  circuit  is  com- 
plete, passing  along  the  positive  wire  to  the  plate  at  its  end, 
where  it  comes  in  contact  with  the  metallic  solution  between  it 
and  the  object  connected  with  the  negative  pole.  This  solu- 
tion, consisting  of  water  and  a  metallic  salt,  is  decomposed  by 
the  circulating  current  in  the  following  manner  : — The  water 
is  decomposed  into  its  elements  oxygen  and  hydrogen,  which, 
being  separated,  rush  in  opposite  directions,  the  hydrogen 
towards  the  object,  whilst  the  oxygen  affects  the  positive  pole 
or  plate ;  and  the  metallic  salt,  infinitesimally  divided  by 
solution,  is  also  broken  up  or  decomposed  into  its  elements  ; 
thus  the  chloride  of  silver  is  separated  into  silver  and  chlorine, 
the  latter  affecting  the  positive  pole,  whilst  the  silver  is  deposited 
on  the  negative  pole.  Take  out  the  object  from  time  to  time 
and  examine  it.  If  the  coating  is  purely  white  (if  silver),  or 
purely  yellow  (if  gold),  the  operation  is  going  on  right,  and 
may  continue  until  the  requisite  amount  of  deposition  has  been 
obtained.  By  this  means  the  metallic  film  thus  deposited  may 
be  made  of  any  thickness  whatever.  Sometimes,  however,  this 
metallic  film  is  not  pure  of  its  kind  ;  on  the  contrary,  it  is 
oftentimes  granular  or  crystalline,  and  at  others  quite  black. 
To  prevent  these  irregularities  is  the  electrotyper's  chief  care, 
and  much  experience  and  patient  study  are  required  before  the 
best  conditions  can  be  obtained  at  once.  Changing  the  dis- 
tance between  the  two  poles,  moving  the  positive  pole  about, 
increasing  or  diminishing  the  thickness  of  the  positive  wire, 
warming  the  electrolyte,  diminishing  or  increasing  the  number 
of  elements  in  the  circuit ;  these  and  other  operations  are  at  times 
necessary  ;  when  to  perform  them  experience  alone  can  teach. 
As  soon  as  the  object  has  received  the  required  thickness  of 
deposit,  it  is  taken  out  of  the  electrolyte,  washed,  dried,  and 
burnished  on  those  parts  which  are  to  appear  brilliant,  whilst 
the  remaining  parts  remain  dead  and  frosted.  Burnishing 
tools  are  sold  for  such  purposes  ;  but,  in  case  of  need,  a  dog's 
long  tooth  may  be  used.  Rouge  is  used  for  polishing  the 
object,  rubbed  on  with  a  tooth-brush  or  wash  leather. 

The  operation  of  plating  or  gilding  over,  the  next  care  is  for 
the  apparatus.  The  dilute  sulphuric  acid,  once  used,  is  thrown 
away  ;  but  the  nitric  acid  is  poured  back  into  the  stock-bottle. 


GILDING  AND  BRONZING.  273 


for  future  use.  The  latter  has,  however,  undergone  decom- 
position during  the  operation,  and  has  become  diluted  with 
water  formed  by  the  elements  liberated  during  the  circulation 
of  the  electric  current  through  the  sulphuric  acid  and  nitric 
acid  ;  and  in  consequence  of  this  gradual  dilution  the  nitric 
acid  becomes  in  course  of  time  too  much  impoverished  for  use, 
and  must  be  replaced  with  concentrated  acid.  Place  the 
porous  earthenware  cell  in  a  dish  of  water  when  it  is  emptied, 
as  also  the  zincs  for  an  hour  or  two  ;  then  remove  them  to 
drain  dry. 

To  Electro-Gild  without  a  Battery. — Take  \  oz.  of  nitric 
and  ^  oz.  muriatic  acid  ;  dissolve  in  these  i  dwt.  of  gold,  gently 
evaporate  until  it  crystallizes,  then  add  2  oz.  of  cyanide  of 
potassium  dissolved  in  1 5  oz.  of  water.  The  article  to  be  gilded 
is  to  be  simply  put  in  the  solution,  and  a  piece  of  clean  zinc 
placed  on  it,  and  moved  from  one  spot  to  another  until  it  is 
sufficiently  covered  with  gold. 

Gilding  on  Steel. — In  any  quantity  of  nitro  muriatic  acid 
{aqua  regia)  dissolve  gold  or  platina,  until,  on  the  application 
of  heat,  no  effervescence  ensues.  Evaporate  the  solution  thus 
formed  to  dryness  by  means  of  a  gentle  heat ;  then  dissolve 
the  dry  mass  thus  formed  in  the  least  possible  amount  of  water. 
Take  the  instrument  known  by  chemists  as  a  separating  funnel, 
which  may  contain  a  liquid  ounce  ;  a  quarter  fill  it  with  the 
liquid,  and  the  other  three  parts  fill  with  the  best  sulphuric 
ether.  The  two  liquids  should  not  mix.  Then  holding  the 
tube  in  a  horizontal  position,  turn  it  round  with  the  finger  and 
thumb.  When  the  ether  has  become  impregnated  with  the 
gold  or  platina,  which  may  be  known  by  its  change  of  colour, 
replace  it  in  a  perpendicular  position,  and  having  stopped  up 
the  orifice  with  a  cork,  let  it  stand  for  twenty-four  hours.  At 
the  end  of  this  time  the  liquid  will  be  divided  into  two  parts, 
the  darkest  coloured  being  below.  Take  out  the  cork  and  let 
the  dark  liquid  flow  off",  and  stop  the  tube  immediately  with 
the  cork.  What  remains  in  the  tube  is  the  gilding  liquid. 
The  article  to  be  gilded  must  be  perfectly  free  from  rust  or 
grease,  and  have  received  the  highest  possible  polish.  The 
process  of  gilding  is  as  follows  : — A  vessel  of  glass  or  unglazed 
ware  having  been  procured,  it  should  be  filled  nearly  to  the 
top  with  the  gilding  hquid.      The  article  should  be  dipped  in 

s 


274  GILDING  AND  BRONZING. 

this  for  a  moment,  and  then  be  plunged  into  clear  water  and 
well  rinsed.  After  having  been  thoroughly  dried  with  blotting- 
paper,  it  should  be  placed  in  a  temperature  of  150°  Fahr.  until 
it  is  heated  throughout,  and  then  polished  with  rouge  and  wash- 
leather  ;  or,  better  still,  be  burnished.  Take  care  that  the 
muriate  of  gold  is  quite  free  from  excess  of  acid,  and  be  careful 
to  follow  exactly  the  above  directions  in  every  particular,  as 
only  by  doing  so  can  perfect  success  be  ensured. 

Electro-Gilding  for  Copper  Chains,  &c. — Take  a  solution 
of  nitro-muriate  of  gold  (gold  dissolved  in  a  mixture  of  aqua- 
fortis and  muriatic  acid),  and  add  to  a  gill  of  it  a  pint  of  ether 
or  alcohol,  then  immerse  your  copper  chain  in  it  for  about 
fifteen  minutes,  when  it  will  be  coated  with  a  film  of  gold.  The 
copper  must  be  perfectly  clean,  and  free  from  oxide,  grease,  or 
dirt,  or  it  will  not  take  on  the  gold. 

Gilding  on  Glass. — Glass  can  be  gilded  in  two  ways,  by 
means  of  fire,  and  by  a*n  adhesive  varnish.  It  is  gilded  by  fire, 
by  tempering  powdered  gold  with  borax  and  gum-water.  The 
mixture  is  applied  to  the  surface  of  the  glass  with  a  soft  pencil 
brush  ;  when  dry,  the  article  is  put  into  a  stove  heated  to  the 
temperature  of  an  annealing  oven  ;  the  gum  burns  off,  and  the 
borax  cements  the  gold  firmly  to  the  article  by  vitrification  ; 
after  this  process,  the  gold  on  the  article  is  burnished.  Gild- 
ing is.  also  effected  by  an  adhesive  drying  varnish,  which  is 
prepared  by  dissolving  gum  anime  in  drying  linseed  oil.  This 
mixture  is  diluted  with  some  oil  of  turpentine,  and  applied  as 
thin  as  possible  to  the  parts  that  are  to  be  gilded.  When  dry, 
the  article  is  to  be  placed  in  a  stove  or  near  a  fireplace,  till  it 
is  warm  enough  to  almost  burn  the  fingers  when  handled,  at 
which  temperature  the  varnish  is  glutinous,  and  a  piece  of  gold 
leaf  applied  will  instantly  adhere.  When  nearly  cold,  it  is 
burnished  ;  but  care  must  be  taken  to  intervene  a  piece  of  very 
thin  India  paper  between  the  gold  and  the  burnisher.  Gold 
size  is  also  used  as  an  adhesive  substance.  The  requisite  bur- 
nishing-tools  can  be  bought  at  any  oil  and  colour  shop. 

Below  we  give  four  methods  of  performing  this  operation  : — 

I .  Take  2  oz.  isinglass,  and  dissolve  in  just  sufficient  water  to 

cover  it ;   when  dissolved,  add  i  quart  rectified  spirits  of  wine 

and  I  quart  water.    This  size  must  be  kept  in  a  bottle  well  corked. 

Thoroughly  clean  and  polish  the  glass ^  and  lay  it  on  a  perfectly 


GILDING  AND  BRONZING.  275 

level  table.  With  a  brush  dipped  in  the  size  flood  the  glass 
oyer,  and  then  with  a  tip  carefully  lay  on  the  gold  leaf,  which 
will  instantly  adhere  to  it.  Then  place  the  glass  on  its  edge 
to  dry,  and  leave  it  for  twenty-four  hours.  On  a  piece  of  paper 
draw  the  required  pattern,  and  with  a  pricker  pierce  holes 
along  the  outline.  Then  lay  this  on  the  gold  surface,  and  dust 
some  powdered  whiting  over  it,  so  that  it  may  penetrate  the 
holes,  and  leave  the  pattern  on  the  gold  underneath.  Care- 
fully remove  the  paper,  and  fill  in  the  outlines  of  the  design 
with  gold  size,  mixed  with  orange  chrome,  and  thinned  with 
boiled  oil  and  turpentine.  When  quite  dry,  remove  the  surplus 
gold  with  a  piece  of  cotton  wool  dipped  in  water,  and  back  the 
glass  with  the  ground  colour. 

2.  First  sketch  on  paper  the  exact  size  and  shape  of  the 
figures  or  letters  required  ;  then  prick  holes  (in  the  outlines) 
through  the  paper  with  a  pin  ;  take  the  paper  and  cover  the 
glass  on  the  front  side  with  it ;  now  dust  the  paper  over  with 
whiting,  so  that  it  goes  through  the  holes  in  the  paper  on  to 
the  glass  ;  remove  the  paper,  and  coat  the  back  of  the  glass 
with  gum  size,  and  before  the  gum  is  dry  take  gold  leaf  and 
place  it  on  the  gum  size,  so  that  the  leaf  covers  the  dust-marks 
on  the  glass.  Do  not  be  particular  about  the  shape  of  the  gold 
leaf  then  ;  only  see  that  the  letters  are  covered.  When  dry, 
paint  the  exact  shape  of  the  letters  on  the  back  of  the  gold 
leaf  with  gold  size,  to  which  has  been  added  some  chrome 
yellow.  When  perfectly  dry,  take  a  little  cotton  wool  and 
water  and  wash  off  all  the  superfluous  gold  leaf.  You  can 
then  shade  or  back  the  letters  with  any  colour. 

3.  Make  a  mixture  of  powdered  gold,  borax,  and  gum  arable 
in  water,  and  brush  the  device  upon  the  glass,  earthenware,  or 
porcelain  with  a  hair  pencil  dipped  in  the  above  mixture  ;  then 
expose  the  article  to  heat  in  an  oven  or  furnace,  by  which 
means  the  gum  is  consumed  and  the  borax  vitrified,  cementing 
the  gold  to  the  glass  or  earthenware,  after  which  it  may  be 
burnished. 

4.  Breathe  on  the  glass,  apply  the  gold  leaf,  then  hold  a  hot 
iron  at  the  back  a  small  distance  off  till  all  the  moisture  is 
dried  out ;  it  will  then  assume  a  bright  appearance.  Then 
immediately  paint  on  the  back  of  it,  or  it  will  get  dim.  By 
this  process  no  size,  or  anything  of  the  kind,  is  needed,  but 
only  a  little  dexterity. 


276  GILDING  AND  BRONZING. 

Silvering  Globes,  Tent  Mirrors,  &c. —  i.  The  mirror  to  be 
silvered  is  suspended,  face  downwards,  in  a  silver  bath  pre- 
pared thus  : — A  large  flat  shallow  vessel  of  glass  or  porcelain 
is  provided  to  contain  the  solution.  One  hundred  and  fifty 
grains  of  nitrate  of  silver  are  dissolved  in  6  oz.  of  distilled 
water,  and  to  this  is  added  pure  liquid  ammonia,  drop 
by  drop,  until  the  precipitate  is  re-dissolved.  2I  oz.  of 
caustic  potash  are  dissolved  in  50  oz.  of  rain-water,  and 
15  oz.  of  this  solution  are  added  to  the  ammoniacal  solu- 
tion, when  a  brown-black  precipitate  is  thrown  down. 
Ammonia  is  again  added,  drop  by  drop,  until  this  pre- 
cipitate is  just  re-dissolved  ;  and  29  oz.  of  distilled  water  are 
then  added  to  the  whole.  To  this  mixture  is  again  added, 
drop  by  drop,  stirring  with  a  glass  rod,  a  strong  solution  of 
nitrate  of  silver,  until  a  precipitate  which  does  not  re-dissolve 
is  formed.  Previous  to  immersing  the  mirror,  one  part  by 
weight  of  powdered  milk-sugar  to  ten  parts  by  measure  of  dis- 
tilled water  must  be  prepared  in  a  separate  vessel,  and  filtered 
until  a  clear  solution  is  obtained.  Then,  to  ten  parts  by 
measure  of  the  silvering  solution  must  be  added  one  part  by 
measure  of  the  milk-sugar  solution,  and,  finally,  50  oz.  of  the 
compound  solution  will  be  sufficient  to  silver  a  speculum  9 
inches  in  diameter.  The  glass  surface  should  be  made  chemi- 
cally clean  by  using  whiting- cream,  free  from  grit,  and  rubbing 
it  off,  when  dry,  with  the  purest  cotton  ;  it  should  then  be 
wetted  with  dilute  nitric  acid,  and  afterwards  washed  with  dis- 
tilled water.  To  suspend  the  mirror,  a  circular  block  of  wood 
is  firmly  cemented  to  its  back  with  marine  glue  or  pitch,  and 
three  pins  inserted  at  equal  distances,  to  which  the  strings  may 
be  fastened.  On  lowering  into  the  bath,  care  must  be  taken 
that  no  air-bubbles  intervene,  that  the  speculum  be  not  deeper 
in  the  liquid  than  half  its  thickness,  and  that  two  inches  at 
least  intervene  between  the  mirror  and  the  bottom  of  the  vessel. 
It  should  remain  in  the  bath  for  four  hours,  by  which  time  the 
process  will  be  completed  ;  it  is  then  removed,  washed  with 
distilled  water,  and  placed  to  dry.  It  is  now  ready  for  polish- 
ing. Rub  the  surface  gently,  first  with  a  clean  pad  of  fine 
cotton  wool,  and  afterwards  with  a  similar  pad  covered  with 
cotton  velvet,  which  has  been  charged  with  fine  rouge. 

2.  The  following  is  one  of  the  cheapest  and  most  durable 
methods  : — Make  an  alloy  of  10  oz,  bismuth,  6  oz.  lead,  and 


GILDING  AND  BRONZING.  277 

4  oz.  tin  ;  put  a  portion  of  this  alloy  into  the  globe,  and  expose 
it  to  a  gentle  heat  until  it  melts  ;  then  turn  the  globe  slowly 
round,  so  that  an  equal  coating  of  the  alloy  is  spread  over  the 
whole  surface.  This,  when  cold,  will  harden,  and  cannot  be 
surpassed  for  durability. 

3.  Take  i  oz.  of  clean  lead,  i  oz.  of  fine  tin,  and  melt  them 
together  in  a  clean  iron  ladle  ;  then  immediately  add  i  oz.  of 
bismuth,  skim  off  the  dross,  take  the  ladle  from  the  fire,  and 
before  the  mixture  sets  add  10  oz.  of  quicksilver,  stirring  all 
well  together. 

4.  The  ^^  Himiid  Process"  as  it  is  called,  is  as  follows  : — 
Four  solutions  are  to  be  prepared — No.  i.  Ten  grammes  of 
nitrate  of  silver  in  100  grammes  of  distilled  water.  No.  2.  An 
aqueous  solution  of  ammonia  standing  at  1 3°  of  Cartier's 
aerometer.  No.  3.  Twenty  grammes  of  pure  caustic  soda  in 
500  grammes  of  distilled  water.  No.  4.  Into  a  solution  of 
common  white  sugar  there  is  to  be  poured  one  cubic  centimetre 
of  nitric  acid  at  36°  ;  it  is  then  to  be  boiled  for  twenty  minutes 
to  produce  interversion.  There  is  then  to  be  added  50  cubic 
centimetres  of  alcohol  at  36°,  and  as  much  distilled  water  as 
will  bring  the  whole  to  500  cubic  centimetres.  Into  a  flask 
holding  about  200  cubic  centimetres  there  is  to  be  poured— 

12  cubic  centimetres  of  solution  No.  i. 
8      „              „  „  No.  2. 

20      „  „  „  Xo.  3. 

50      ,,  „  of  distilled  water. 

The  liquid  should  remain  perfectly  limpid.  This  solution  is  al- 
lowed to  repose  for  twenty-four  hours.  Now  as  to  its  application. 
The  surface  of  the  glass  to  be  silvered  must  be  scrupulously 
cleaned,  and  then  passed  over  with  a  ball  of  cotton  wet  with 
nitric  acid  at  36°,  and  finally  washed  with  distilled  water,  and 
drained  from  this  and  placed  upon  supports  at  the  surface  of 
a  bath  composed  of  the  silvering  fluid  as  above,  to  which  has 
been  added  one-tenth  or  one-twelfth  of  its  bulk  of  solution 
(No.  4).  Under  the  influence  of  diffused  daylight,  the  surface 
to  be  silvered  (immersed  in  the  bath)  is  seen  to  become  first 
yellow,  then  brown,  and  in  two  to  five  minutes  the  silver  will 
be  found  to  be  uniformly  spread  over  the  glass  ;  in  ten  or  fifteen 
minutes  the  coat  will  be  found  to  be  thick  enough.  The  glass 
is  then  to  be  washed  in  common  and  afterwards  in  distilled 


278  GILDING  AND  BRONZING. 

water,  and  left  to  dry  in  free  air.  When  dry,  the  surface  pre- 
sents a  perfect  metaUic  polish,  covered,  as  it  were,  by  a  thin 
veil.  It  is  then  polished  with  chamois  leather  and  the  finest 
rouge  ;  a  metallic  surface  of  the  utmost  brilliancy  will  be  the 
result.  The  gramme  =  I5'434  grains.  Cubic  centimetre  = 
•165  of  a  cubic  inch. 

Silvering  Brass. — Brass  and  copper  are  the  only  metals 
that  can  be  silvered  without  a  battery.  The  process  of  silver- 
ing brass  is  thus  described  : — In  8  oz.  of  water  dissolve  2  oz. 
of  cyanide  of  potassium,  and  in  the  same  quantity  of  water  i 
dr.  of  nitrate  of  silver.  Into  the  vessel  containing  the  silver 
throw  about  half  a  spoonful  of  common  salt ;  stir  this  well  with 
a  glass  rod  until  the  silver  is  precipitated.  Mix  a  little  salt 
and  water,  and  add  a  few  drops  to  the  solution  after  it  has  had 
time  to  settle.  If  any  cloudiness  follow,  more  salt  must  be 
added.  When  the  addition  of  salt  water  has  ceased  to  have 
any  effect,  carefully  pour  off  the  water  and  preserve  the  deposit. 
Wash  this  deposit  two  or  three  times  in  boiling  water,  and  then 
carefully  dry.  Place  this  powder  in  a  vessel,  and  pour  on  it 
about  a  pint  of  water,  and  add  the  cyanide  solution  about  ^  oz. 
at  a  time  until  the  precipitate  is  dissolved,  then  add  enough 
water  to  make  about  a  quart.  While  adding  the  cyanide  solu- 
tion stir  well.  If  when  dipping  the  article  into  this  solution 
the  silver  deposits  too  quickly,  more  water  must  be  added  ; 
if  it  coats  very  slowly,  the  solution  must  be  strengthened  with 
more  precipitate.  This  must  be  also  done  whenever  the  solu- 
tion, becomes  weak.  The  solution  when  in  use  should  be  kept 
at  a  temperature  of  from  60°  to  70°  of  heat.-  After  polishing 
and  burnishing,  the  article  silvered  should  be  as  brilliant  and 
durable  as  can  be  wished. 

Silvering-Powder  for  Coating  Copper. — Take  60  grains  of 
nitrate  of  silver ;  60  grains  of  common  salt,  and  7  drs.  of 
cream  of  tartar.  Mix  them,  and  moisten  with  water,  and  then 
apply. 

Silvering  Mirrors. — The  process  of  employing  a  layer  of 
tin-foil  and  mercury,  commonly  but  falsely  called  "  silvering," 
is  as  follows  : — A  sheet  of  tin-foil  corresponding  to  the  size  of 
the  plate  of  glass  is  evenly  spread  on  a  perfectly  smooth  and 
solid  marble  table,  and  every  wrinkle  on  its  surface  is  carefully 
rubbed   down  with  a  brush.      A  portion  of  mercury  is  then 


GILDING  AND  BRONZING.  279 

poured  on,  and  rubbed  over  the  foil  with  a  clean  piece  of  very- 
soft  woollen  stuff,  or  a  hare's  foot,  after  which  two  rules  are 
applied  to  the  edges  and  mercury  poured  on  to  the  depth  of  a 
crown  piece,  when  any  oxide  on  the  surface  is  carefully  removed, 
and  the  sheet  of  glass,  made  perfectly  clean  and  dry,  is  slid 
along  over  the  surface  of  the  liquid  metal,  so  that  no  air,  dirt, 
or  oxide  can  possibly  either  remain  or  get  between  them. 
When  the  glass  has  arrived  at  its  proper  position,  gentle  pres- 
sure is  applied,  and  the  table  sloped  a  little  to  carry  off  the 
waste  mercury,  after  which  it  is  covered  with  flannel  and  loaded 
with  heavy  weights.  In  twenty-four  hours  it  is  removed  to  a 
wooden  table,  and  further  slanted;  and  this  position  is  pro- 
gressively increased  during  a  month,  until  it  becomes  perpen- 
dicular. 

Picture-Frame  Stain. — To  stain  a  picture  frame  black, 
procure  some  logwood  chips,  and  boil  them  ;  give  your  frame 
a  coat  of  the  boiling  hquid.  You  will  find  this  generally  raise 
a  roughness  on  the  wood  ;  let  it  dry,  and  then  use  sand-paper  ; 
then  give  it  another  coat  of  the  warm  liquid,  and  before  it  dries 
give  it  a  coat  of  iron  liquor.  If  you  want  a  good  job,  put  a 
little  ivory-black  in  your  polish. 

To  Gild  Picture  Frames. — Provide  yourself  with  the  follow- 
ing articles  :  a  cushion,  made  by  covering  a  board  of  about  8 
in.  square  with  a  double  thickness  of  flannel,  and  over  that  a 
piece  of  buff  leather,  and  fastening  it  tight  round  the  edges  ;  a 
palette  knife,  for  cutting  the  leaves  into  the  requisite  sizes  ;  a 
tip,  a  fitch  pencil,  a  ball  of  cotton,  and  a  large  camel's -hair 
brush.  The  frame  intended  to  be  gilt  should  first  be  well  sized, 
and  then  done  over  with  seven  or  eight  coats  of  size  and  whit- 
ing, so  as  to  cover  it  with  a  body  of  considerable  thickness. 
Having  got  a  sufficient  quantity  of  whiting  on,  it  must  be  care- 
fully cleaned  off,  taking  care  to  free  all  the  cavities  and  hol- 
lows ;  it  is  then  to  receive  a  coat  of  size,  and  be  left  till  nearly 
dry.  The  work  being  thus  prepared,  place  it  a  little  declining 
from  you,  and  having  ready  a  cup  of  clean  water,  and  some 
hair  pencils,  moisten  a  part,  of  the  work,  and  apply  the  gold 
leaf  by  the  tip  to  the  part.  The  gold  will  immediately  adhere, 
and  is  then  to  be  pressed  down  by  the  ball  of  cotton.  Proceed 
thus  until  the  whole  is  finished,  leave  by  for  twenty-four  hours, 
and  then  burnish  the  prominent  parts  with  an  agate  burnisher. 


28o  .•  GILDING  AND  BRONZING. 

Gilding  and  Plating. — The  following  instructions  are  con- 
densed from  an  article  by  Professor  Towler,  a  capable  and 
experienced  instructor  : — 

The  first  thing  required  is  a  galvanic  battery.  There  is  a 
great  variety  of  galvanic  batteries  to  be  had,  but  we  prefer  a 
Grove's  battery.  A  single  element  consists  of  a  cylinder  of 
zinc,  a  thin  plate  of  platinum,  a  tumbler,  a  cell  of  porous  or 
unglazed  earthenware,  two  binding-screws,  two  solutions  (dilute 
sulphuric  acid  and  concentrated  nitric  acid),  two  connecting- 
wires,  and  a  plate  of  silver  and  one  of  gold  (a  two-shilling  piece 
for  one,  and  a  gold  dollar  for  the  other).  Two  of  these  elements 
will  be  sufficient  for  almost  all  ordinary  operations  of  gilding, 
and  sometimes  only  one  is  required.  The  zincs,  plates  of  pla- 
tinum, porous  cells,  binding-screws,  tumblers,  and  connecting- 
wires,  can  be  bought  already  prepared  for  electrolyte  operations 
and  ready  for  mounting.  Mix  one  fluid  ounce  of  commercial 
sulphuric  acid  with  ten  fluid  ounces  of  water  for  one  solution. 
The  strongest  aquafortis  or  commercial  nitric  acid  is  suitable 
for  the  other  solution. 

In  the  second  place  a  silver  and  a  gold  solution  have  to  be 
prepared,  and  kept  on  hand  ready  for  use.  Each  of  these  solu- 
tions is  denominated  an  electrolyte,  and  the  art  of  decomposing 
such  a  solution  by  means  of  an  electric  current  is  known  by  the 
name  of  electrolysis.  To  prepare  the  silver  sohition,  take  a 
solution  of  nitrate  of  silver,  and  add  to  it  a  solution  of  common 
salt  as  long  as  any  white  precipitate  is  produced.  Perform  this 
operation  in  a  darkened  room,  because  the  white  precipitate 
(chloride  of  silver)  is  very  sensitive  to  light,  thereby  changing 
into  a  violet-coloured  powder,  which  is  insoluble  in  the  fluid 
into  which  it  is  subsequently  mixed.  As  soon  as  the  precipitate 
has  completely  subsided,  pour  off  the  supernatant  fluid,  and 
add  to  it  a  few  drops  of  the  salt  solution  ;  if  no  milkiness  is 
produced,  the  silver  has  all  been  removed  as  chloride,  and  con- 
sequently the  fluid  may  be  thrown  away  as  useless.  Mix  the 
white  chloride  with  rain-water,  and  stir  the  mixture  with  a  glass 
rod,  and  allow  the  precipitate  to  settle  again ;  this  is  called 
washing  the  precipitate.  When  the  precipitate  has  subsided, 
the  fluid  part  is  poured  off,  and  the  residue  is  again  washed. 
This  operation  is  repeated  several  times,  and  the  chloride, 
finally  separated  by  decantation  from  the  wash-water,  is  ready 
for  the  next  treatment.      Make  a  saturated  solution  of  cyanide 


GILDING  AND  BRONZING. 


281 


of  potassium  in  rain-water — that  is,  add  lumps  of  the  cyanide 
as  long  as  it  is  dissolved,  and  finally  a  small  part  is  left  undis- 
solved. The  water  is  then  saturated  with  the  salt.  Pour  this 
saturated  solution  of  the  cyanide  upon  the  chloride  of  silver, 
and  keep  pouring  and  stirring  until  the  chloride  is  entirely 
dissolved.  Filter  the  solution,  and  dilute  as  follows  : — Silver 
electrolyte  :    saturated   solution    of   the    chloride   of   silver   in 


cyanide  of  potassium,  4  oz. 
is  then  ready  for  use. 


rain-water,  12  oz.     The  solution 


Picture- Frame  Making. — The  following  is  a  simple  and 
easy  plan  for  making  picture  frames.  Take  a  common  deal 
board  9  in.  wide  and  i  in.  thick ;  cut  it  into  four  slips,  run  a 
rabbit  plane  on  one  edge,  for  the  glass,  picture,  and  back  to  fit 
into.  Cut  it  into  lengths,  according  to  the  size  of  the  pictures  ; 
countersink  the  sides  into  the  top  and  bottom ;  one  screw  in 
each  angle,  put  in  from  the  back,  will  keep  them  firmly  to- 
gether. A  cord  round  the  projections  at  the  top  will  serve  to 
hang  the  picture. 

Deal  may  be  stained  a  dark  oak-colour,  by  giving  it  two  or 
three  coats  of  a  solution  of  i  oz.  bichromate  of  potass,  and  2 
oz.  of  bluestone,  in  y^ 

1 2  oz.  of  water ; 
after  which,  apply 
plain  drying  oil,  and 
finish  with  copal 
varnish.  The  oil 
deepens  the  colour 
and  brings  out  the 
natural  graining. 
» For  clamping  pic- 
ture frames,  pro- 
ceed thus  :  —  Cut 
four  pieces  as  No.  i ; 
drill  a  hole  through 
as  shown ;  cut  a 
small  channel  as 
shown  ;  cut  two  pieces  as  No.  2  and  3  six  inches  long  ;  drill  No. 
2  half-way  through  for  end  of  screw,  the  same  as  the  ordinary 
clamp.  No.  3  is  to  be  tapped  to  fit  screw.  In  addition 
two  small  holes  same  size  as  through  angles  and  as  shown. 


282 


GILDING  AND  BRONZING. 


Get  a  length  of  catgut  about  \  in.  thick.  Put  it  through  the 
angles  and  No.  3.  Before  glueing,  see  that  the  catgut  is  about 
the  size  of  the  frame.  Then  glue  and  put  the  angle-pieces  on, 
and  screw  up  as  shown  in  No.  4.  They  can  all  be  made  of 
beech  i  in.  thick.  This  plan  is  expensive,  and  rather  slow. 
Prints  must  have  a  glass  over  them,  and  so  be  secured  from 
the  entrance  of  dust,  flies,  and  damp.  The  glass  of  each  frame 
is  laid  in  with  a  composition  like  plaster,  blackened  to  suit  the 
dark  frames  ;  and,  besides  this,  glass  is  pasted  all  round  inside 
to  the  frame  with  a  narrow  strip  of  paper.  Within  the  glass  is 
the  gilt  moulding,  which  thus  serves  to  keep  the  print  and  the 
glass  a  quarter  of  an  inch  apart.  The  print,  being  attached  by 
its  edges,  or  its  corners,  to  the  backboard,  is  put  in  over  the  gilt 
moulding,  and  the  whole  of  the  back  securely  pasted  over  with 
strong  paper.  The  only  prints  that  turn  yellow  are  those  pasted 
on  to  canvas  stretchers.  This  is  probably  caused  by  the  paste. 
The  paste  to  be  used  for  all  prints  and  drawings  should  be 

shoemakers'  paste, 
which  has  alum  in 
it;  and  besides,  not 
breeding  insects, 
will  attach  paper  to 
wood  thoroughly. 
The  putty,  paste, 
&c.,  used  must  be 
quite  dried  after 
each  part  of  the 
process  of  framing, 
before  proceeding 
to  paste  up  the  back. 
Theprint  itself  must 
be  also  thoroughly 
dried.  The  best 
composition  for  pic- 
ture-frame cornices 
is  composed  of  size  and  whiting.  .The  best  size  is  made  by 
well-soaking  buffalo  skin,  and  then  boihng  it  to  the  consistency 
of  jelly.      For  touching  up  old  frames  the  common  size  will  do. 


Compo  Ornaments  for  Picture  Frames. — In  a  quart  of 
water    boil    3 J   lbs.    of  the  best  glue,  and  in   3  gills  of  raw 


GILDING  AND  BRONZING.  "2S3 

linseed  oil  melt  \\  lbs.  of  white  resin.  When  these  ingredients 
are  well  boiled,  let  them  simmer  together  in  a  large  vessel  for 
about  half  an  hour,  stirring  the  mixture,  and  taking  care  it  does 
not  boil  over.  When  this  is  done,  pour  out  the  mixture  into  a 
large  quantity  of  finely-ground  whiting,  and  roll  it  to  the  con- 
sistency of  dough,  and  it  is  then  ready  for  use. 

Composition  Or?iaments. — Dissolve  \  lb.  of  glue  in  2  quarts 
of  water.  Boil  together  i  lb.  of  resin,  \  gill  of  Venice  turpen- 
tine, and  I  gill  of  linseed  oil.  Put  these  two  mixtures  into  one 
kettle,  and  boil  together,  stirring  well  until  all  the  water  has 
evaporated  ;  then  add  finely-powdered  whiting  until  the  mass 
has  attained  the  consistency  of  putty.  This  composition 
becomes  hard  when  cold,  but  when  warm  may  be  readily 
moulded  to  any  pattern  required,  and  is  more  durable  than 
wood. 

Gilding  Organ  Pipes. — After  being  perfectly  cleaned,  the 
pipes  should  be  painted  over  with  flat  lead  colour  finely  ground, 
mixed  with  plenty  of  patent  driers,  and  a  little  boiled  linseed 
oil.  (Two  coats  may  be  given,  the  first  to  be  thoroughly  dry 
before  the  second  is  applied.)  After  the  second  coat  is 
thoroughly  dry,  the  surface  must  be  covered  with  gold  size 
(which  can  be  purchased  ready  prepared  at  the  colour-shops, 
or  made  as  directed  (page  286).  When  the  gold  size 
is  nearly  dry,  or  in  a  "  tackey "  or  slightly  sticky  state, 
the  gold  leaf  must  be  applied  carefully,  and  pressed  down 
evenly  with  a  soft  ball  of  cotton  wool.  After  a  short  time  all 
the  loose  particles  of  gold  may  be  removed  by  carefully  rubbing 
with  the  ball  of  cotton  wool.  The  coloured  patterns  are  pro- 
duced by  the  following  method  : — Sheets  of  glazed  paper, 
having  the  patterns  it  is  desired  to  colour  cut  out,  are  placed 
over  the  gilded  parts,  and  oil  colour  dabbed  carefully  through 
with  a  soft  brush.  The  colours  should  be  mixed  with  patent 
driers,  turps,  and  very  little  oil,  to  make  them  flat.  If  two  or 
more  colours  are  desired  in  the  pattern,  papers  for  each  diffe- 
rent colour  in  the  pattern  must  be  cut  out. 

Imitation  Silvering  or  Gilding. — A  small  quantity  of  melted 
tin  is  poured  into  a  box,  \yhich  is  then  closed  and  violently 
shaken,  so  as  to  reduce  the  tin  to  a  fine  powder.  This  powder 
is  mixed  with  a  small  quantity  of  size  or  thin  glue.      The  article 


284  GILDING  AND  BRONZING. 

to  be  gilded  or  silvered  is.  then  coated  and  allowed  to  nearly- 
dry.  Burnish  with  an  agate  burnisher,  and,  if  required  to 
imitate  silver,  coat  with  seed  lac  varnish  ;  but  if  to  imitate  gold, 
colour  the  varnish  with  a  mixture  of  gamboge  and  anatto.  The 
chief  difficulty  is  to  obtain  the  proper  proportion  of  size  to  tin  ; 
for  if  too  much  size  is  used,  the  burnisher  will  produce  no  effect  ; 
and  if  too  little,  the  tin  will  crumble  off. 

Mosaic  Gold. — To  make  what  is  termed  "  mosaic  gold," 
heat  together  in  a  crucible  or  iron  ladle  a  mixture  of  six  parts 
of  tin,  three  of  mercury,  three  of  sal-ammoniac,  and  about  the 
same  of  flowers  of  sulphur.  Most  of  these  will  be  sublimed  by 
the  heat,  and  a  solid  shining  substance  of  the  appearance  of 
gold  will  remain. 

Bronze  and  Bronzing.  —Bronzing  is  of  two  kinds  :  the  pur- 
pose of  the  one  is  to  cover  objects  of  all  kinds  with  a  coating 
which  shall  give  them  the  appearance  of  bronze,  while  the 
other  kind  of  bronzing  modifies  the  surface  of  various  metals, 
and  protects  them  from  the  action  of  the  air.  The  operation 
varies  according  to  the  nature  of  the  body  to  be  bronzed,  as 
explained  below. 

Bronzing  Plaster  Casts. — To  cover  plaster  casts,  statuettes, 
&c.,  with  a  very  durable  green  coating,  which  will  protect 
them  against  atmospheric  agencies,  and  give  them  a  colour 
resembling  antique  bronzes,  employ  ferro-cupreous  soap,  which 
is  prepared  thus  : — A  soap  is  made  with  linseed  oil  and  caustic 
soda  ;  a  concentrated  solution  of  sea-salt  is  added,  and  the 
whole  evaporated  until  the  soap  begins  to  float  in  grains  on  the 
surface  ;  it  is  then  filtered  through  a  metal  strainer,  and  the 
grains  of  soap  thus  collected  are  dissolved  in  boiling  water,  and 
the  solution  again'  filtered  to  remove  impurities.  On  4;he  other 
hand,  dissolve  in  hot  water  four  parts  of  sulphate  of  copper 
and  one  part  of  sulphate  of  iron  ;  then  pour  the  liquid  into  the 
solution  of  soap  slowly,  and  continue  to  stir  the  mixture  until 
no  more  precipitate  is  formed.  This  precipitate  is  the  ferro- 
cupreous  soap  named  above — that  is  to  say,  a  mixture  of 
brownish-red  ferruginous  soap,  and  a  very  beautiful  green 
cupreous  soap.  These  two  colours,  when  mixed,  yield  a  brown- 
ish-green tint,  very  similar  to  the  vej'd  antique.  To  purify  this 
soap,  collect  it  upon  a  filter,  and  boil  it  for  a  few  minutes  in  the 


GILDING  AND  BRONZING.  285 

solution  of  iron  and  copper;  then  wash  it  in  pure  boihng  water, 
next  in  cold  water,  then  drain  and  dry  it  as  much  as  possible. 

To  bronze  a  plaster  cast.,  mix  in  a  bain  7narie  30  oz.  of 
refined  boiled  linseed  oil,  16  oz.  of  ferro- cupreous  soap  (made 
as  directed  above),  and  10  oz.  of  white  wax  ;  when  the  mixture 
is  melted,  apply  it  with  a  brush  upon  the  plaster  (heated  in  an 
oven  to  a  temperature  of  180°  to  200°).  Repeat  the  apphca- 
tion  where  needed,  and  leave  the  cast  in  the  stove  for  a  few 
minutes.  The  mixture  thoroughly  penetrates  the  plaster,  filling 
its  pores,  without  in  any  respect  injuring  the  dehcacy  of  detail. 
When  small  pieces  are  to  be  prepared,  they  may  be  immersed 
in  the  melted  mixture,  drained,  and  placed  before  the  fire  until 
the  mixture  has  completely  sunk  into  the  plaster.  Finish  by 
rubbing  the  surface  with  a  tuft  of  cotton.  Plaster  figures  may 
be  silvered  by  rubbing  them  with  an  amalgam  formed  of  equal 
parts  of  mercury,  bismuth,  and  tin,  and  afterwards  covering 
them  with  a  coat  of  pale  varnish.  A  metallic  lead-grey  coloicr 
is  imparted  to  the  figures  by  brushing  them  over  with  fine 
plumbago  or  graphite. 

Another  method. — Go  over  the  figure  with  isinglass  size  until 
every  part  is  covered,  and  the  plaster  has  ceased  to  absorb. 
Then  go  over  the  whole  with  a  stiff  brush,  taking  care  that 
none  of  the  size  lodges  in  the  more  dehcate  parts  of  the  figure. 
When  it  is  dry,  with  a  brush  containing  just  enough  thin  oil 
gold  size  to  damp  it,  go  over  the  figure,  and  set  it  aside  to  dry 
for  about  forty-eight  hours.  Touch  then  the  whole  figure  with 
bronze  pow^der,  and  let  it  stand  for  twenty-four  hours  ;  then 
with  a  soft  brush  remove  all  the  loose  powder,  particularly 
from  the  more  prominent  parts. 

Bronze  Powder. — Dissolve  copper  filings  in  aquafortis  ; 
when  the  copper  has  impiegnated  the  acid,  pour  off  the  solution, 
and  put  into  it  some  pieces  of  iron,  or  iron  filings  ;  the  effect 
of  this  will  be  to  sink  the  powder  to  the  bottom  of  the  acid  ; 
pour  off  the  liquor,  and  wash  the  powder  in  successive  quan- 
tities of  fresh  water.  When  the  powder  is  dry,  it  is  to  be 
rubbed  on  the  figure  with  a  soft  cloth,  or  piece  of  leather  ;  but 
observe  that,  previously  to  the  application  of  the  bronze  powder, 
a  dark  blackish  sort  of  green  is  to  be  laid*  on  the  figure  ;  and 
if  you  wish  the  powder  to  adhere  stronger,  mix  it  with  gum- 
water.      Lay  it  like  paint,  with  a  cameFs-hair  brush,  or  pre- 


286  GILDING  AND  BRONZING. 

viously  trace  the  parts  to  be  bronzed  with  gold  size,  and  when 
nearly  dry  rub  the  powder  over  it. 

Grold  Size. — Take  i  lb.  of  linseed  oil,  add  4  oz.  gum  animi 
gradually,  stirring  well  over  a  clear  fire  until  the  whole  is  dis- 
solved. Then  boil  until  a  drop,  when  taken  out  and  cooled, 
becomes  as  thick  as  tar  ;  strain  through  a  coarse  cloth,  and 
put  aside  ready  for  use.  When  used,  add  as  much  vermilion 
as  will  make  it  opaque,  and  thin  with  oil  and  turpentine. 

Gold  Powder. — Grind  leaf-gold  with  virgin  honey  until  the 
leaves  are  thoroughly  broken  up  and  divided  ;  then  stir  the 
whole  in  a  basin  of  water  until  the  honey  is  dissolved.  Leave 
the  basin  then  undisturbed  for  a  short  time ;  and  when  the  gold 
has  subsided,  pour  off  the  water,  adding  several  fresh  quantities 
until  all  the  honey  is  washed  away,  after  which  filter  and  dry 
for  use. 

Copper  Bronze. — Copper  articles  are  bronzed  by  the  follow- 
ing process  : — Dissolve  in  vinegar  two  parts  of  sal-ammoniac 
and  four  parts  of  verdigris.  Boil,  skim,  and  dilute  with  water 
until  a  white  precipitate  ceases  to  fall.  Thoroughly  cleanse 
the  articles  from  grease  or  other  impurities,  and  set  them  in  a 
pan.  Boil  the  above  solution,  and  pour  it  over  the  articles, 
and  then  boil  them  in  it  until  a  reddish-brown  colour  is  pro- 
duced. When  this  is  the  case,  which  must  be  ascertained  by 
frequent  inspection,  the  articles  must  be  at  once  removed,  and 
then  repeatedly  washed  and  dried.  The  solution  must  not  be 
too  strong,  as  should  it  be  so,  the  bronze  will  come  off  with 
friction,  or  turn  green  when  exposed  to  the  atmosphere.  The 
best  bronze  for  copper  is  that  used  by  urn-makers  and  medal- 
lists. It  is  essential  that  the  preparation  of  iron  should  be  of 
a  good  quality  and  free  from  grit,  and  that  it  shall  be  mixed  in 
boiled  clear  water  until  it  is  of  the  thickness  of  cream.  The 
copper  articles  being  ready,  the  surface  must  be  coated  with  the 
red  cream,  and  then  held  over  a  very  hot  fire  which  is  free  from 
sulphur,  and  turned  round  and  round  so  that  all  parts  may 
come  in  contact  as  soon  as  possible.  To  perform  this  opera- 
tion well  great  practice  is  required.  The  articles  are  subse- 
quently burnished. 

Brown  Bronze  Dip. — Iron  scales,  i  lb.  ;  arsenic,  i  oz.  ; 
muriatic  acid,  i  lb.  ;  zinc  (solid),  i  oz.  Let  the  zinc  be  kept 
in  onlv  while  it  is  in  use. 


GILDING  AND  BRONZING.  287 


Green  Bronze  Dip- — Wine  vinegar,  2  quarts  ;  verditer  green, 
2  oz,  ;  sal  ammoniac,  i  oz.  ;  salt,  2  oz,  ;  alum,  \  oz.  ;  French 
berries,  8  oz.  ;   boil  the  ingredients  together. 

Olive  Bronze  Dip  for  Brass. — Nitric  acid,  i  oz.  ;  muriatic 
acid,  2  oz.  ;  add  titanium  or  palladium  ;  when  the  metal  is 
dissolved,  add  2  gallons  of  pure  soft  water  to  each  pint  of 
the  solution. 

To  Bronze  Gun  Barrels.—  Dilute  nitric  acid  with  water  and 
rub  the  gun  barrels  with  it  ;  lay  them  by  for  a  few  days,  then 
rub  them  with  oil  and  polish  them  with  beeswax. 

Green  Bronze. — Bronzes  steeped  for  several  days  in  a  strong 
solution  of  common  salt,  if  washed  in  water  and  allowed  to  dry 
slowly,  become  permanently  green  ;  or  a  strong  solution  of 
sugar  with  a  little  oxalic  acid  will  produce  the  green  colour.  A 
dilute  solution  of  ammonia  allowed  to  dry  on  the  surface  pro- 
duces an  evanescent  green. 

Black  Bronze  for  Brass. — Put  31  lbs.  of  scales  that  fall 
from  the  red  iron  hammered  at  the  blacksmith's  anvil  into 
7  lbs.  spirits  of  salt,  and  both  into  an  earthenware  pan,  in 
which  let  them  stand  for  about  five  hours,  covered  close,  to 
keep  in  the  fumes ;  stir  it  three  or  four  times ;  strain  off  into  a 
stone  bottle,  into  which  put  i  i  lbs.  of  white  powdered  arsenic  ; 
shake  well,  let  it  stand  for  a  day  or  two,  and  the  mixture  is 
ready  for  use.  Before  using  cleanse  the  brass  from  grease 
either  with  emery-cloth  or  a  brush,  with  sand  and  plenty  of 
water.  Next  dip  the  brass  in  the  bronze  until  it  is  black;  then 
wash  it  in  clean  water,  then  in  boiling  water — for  thus  heat  is 
given  to  dry  the  work  and  preserve  the  bronze.  A  soft  black- 
lead  brush  is  then  applied  with  some  good  lead;  then  the  article 
is  to  be  lacquered  with  a  very  pale  lacquer  and  heated  in  an 
oven  or  on  a  hot  plate  to  set  it  hard.  For  green  do  the  same 
work  with  green  lacquer  for  brass,  to  be  had  in  any  colour- 
shop.  To  make  iron  green.,  cleanse  it  first  from  grease,  then 
give  it  a  coat  of  blacklead,  next  one  of  green  lacquer  ;  then 
make  the  article  hot  in  an  oven  or  on  a  plate,  put  on  another 
coat  of  lacquer,  and  heat  finally. 

Black  Bronzing  Iron  and  Steel.— The  following  method  of 
colouring  iron  and  steel  to  serve  both  as  an  ornamentation  and 


288  GILDING  AND  BRONZING. 

preservative  from  rust  is  the  discovery  of  M.  Thirault,  and  has 
been  successfully  adopted  in  many  factories.  The  following 
mixtures  are  not  the  only  ones  that  can  be  employed,  but  are 
given  as  examples  : — 

Liquid  No.  i. — A  mixture  of  bichloride  of  mercury  and  sal- 
ammoniac. 

Liquid  No.  2. — A  mixture  of  perchloride  of  iron,  sulphate 
of  copper,  nitric  acid,  alcohol  and  water. 

Liquid  No.  3. — Perchloride  and  protochloride  of  mercury, 
mixed  with  nitric  acid,  alcohol  and  water. 

Liquid  No.  4. — A  weak  solution  of  sulphide  of  potassium. 

A  sponge  is  slightly  moistened  with  Hquid  No.  i,  and  rubbed 
upon  the  metal,  previously  well  cleaned,  and  when  quite  dry,  a 
second  application  of  the  liquid  is  made  ;  the  crust  of  oxide 
formed  upon  the  application  of  the  liquid  is  removed  by  a  wire 
brush,  and  the  metal  rubbed  with  a  clean  piece  of  rag,  and  this 
operation  is  repeated  after  every  fresh  apphcation  of  the  several 
liquids.  Several  coats  of  liquid  No.  2  are  then  applied,  and 
also  of  No.  3,  with  a  full  sponge  ;  and  after  drying  for  ten 
minutes,  the  pieces  of  metal  are  thrown  into  water  heated 
nearly  to  the  boiling-point,  where  they  are  allowed  to  remain 
five  or  ten  minutes,  according  to  their  size.  After  being  cleaned, 
they  are  again  covered  with  several  coatings  of  liquid  No.  3, 
afterwards  with  a  strong  coating  of  No.  4,  and  again  immersed 
in  the  bath  of  hot  water.  When  removed  from  the  bath,  the 
pieces  are  dried  and  wiped  several  times  with  carded  cotton, 
dipped  in  liquid  No.  3,  diluted  each  time  with  an  increased 
quantity  of  water  ;  then  they  are  rubbed  with  a  little  olive 
oil  and  wiped  ;  they  are  again  immersed  in  water  heated  to 
140°  Fahr.,  and  upon  being  removed  from  it  they  are  rubbed 
briskly  with  a  woollen  rag,  and,  lastly,  with  oil.  The  pieces 
thus  treated  are  of  a  beautiful  glossy  black,  especially  if  they 
have  been  polished.  Iron  and  cemented  steel  are  well  adapted 
to  receive  this  black  polish  ;  cast  steel  is  still  better  adapted 
for  it,  as  it  assumes  a  more  uniform  brilliancy.  Cast  iron  pre- 
sents more  difficulties,  because  it  does  not  assume  the  same 
tint  all  over  equally. 

Bronzing  Wood. — First  cover  the  wood  with  a  uniform  coat- 
ing of  glue,  or  of  drying  oil,  and  when  nearly  dry  the  bronze 
powder,   contained    in    a  little    bag,  is  dusted  over   it.      This 


PYROTECHNY.  289 


bronze  powder  is  made  of  various  materials,  such  as  brass,  tin, 
gold,  ormolu  pulverized,  or  of  metallic  copper  obtained  in 
a  pulverulent  form  by  precipitation  from  its  saline  solutions  by 
means  of  iron.  [The  process  is  as  follows  : — They  begin  with 
preparing  the  proper  alloy,  either  of  copper  and  zinc  or  copper 
and  tin,  in  due  proportions.  These  alloys  are  cast  in  plates 
and  hammered  out  into  sheets  by  steam  hammers.  After  they 
have  been  brought  to  the  thickness  of  a  stout  sheet  of  paper, 
these  sheets,  with  frequent  intervening  annealings,  go  through 
a  system  of  rollers,  from  whence  they  go  to  the  acid  room, 
where  diluted  acid  and  washing  with  water  removes  the  scale 
and  stains.  The  cutting  of  the  sheets  into  shreds  is  the  next 
operation,  after  which  the  shreds  of  fine  sheet  metal  are  well 
mixed  with  dextrine,  to  avoid  the  dust  of  the  next  stage  of 
manufacture.  Powerful  quartz  crushers  then  soon  reduce  the 
metal  to  coarse  powder,  ready  to  go  to  the  grinding  and  polish- 
ing mills,  which  consist  of  tempered  wavy  steel  plates,  over 
which  steel  rods  travel  at  a  great  speed,  grinding  and  polishing 
the  bronze  at  the  same  time,  and  the  quahty  or  grain  of  the 
article  is  determined  by  the  length  of  time  to  which  it  is  sub- 
jected to  the  operation  of  these  mills.  Washing  and  straining 
the  bronze  powder,  to  get  rid  of  accidental  impurities  of  the 
dextrine,  are  the  next  steps,  after  which  the  bronze  is  put  into 
bags  of  fine  but  strong  cloth,  and  exposed  to  the  pressure  of  a 
hydraulic  press,  to  squeeze  the  water  out  and  lessen  its  bulk. 
Drying  at  a  low  temperature  and  packing  into  pound  or  ounce 
packages  makes  the  article  ready  for  the  market.]  The  sur- 
face of  the  objects  is  afterwards  rubbed  with  a  piece  of  moist 
rag,  or  the  bronze  powder  may  be  previously  mixed  with  the 
drying  oil  and  applied  with  a  brush. 

Bronzing  Paper. — When  bronzing  paper,  use  gum  instead  of 
drying  oil.     When  dry,  the  paper  should  be  burnished. 

Pyrotechny. — A  few  of  the  simple  and  more  effective  fire- 
works are  given  below.  The  utmost  care  should  be  observed 
in  all  preparations  of  the  kind — in  filHng,  mixing,  and  exhibit- 
ing— as  most  of  the  ingredients  are  highly  explosive,  either  on 
concussion  or  at  a  comparatively  low  temperature. 

Coloured  Fires. — The  following  may  be  burnt  open  : — Red. 
—  I.   Nitrate  of  strontia  12  parts  ;  chlorate  of  potash,  3  parts  ; 

T 


290  PYROTECHNY, 


shellac,  i  part.  The  strontia  to  be  heated  until  deprived  of  its 
water  of  crystallization,  then  finely  powdered.  The  chlorate  and 
shellac  also  powdered,  and  all  mixed  intimately.  The  rationale 
of  this  formula  is  that  the  chlorate  supplies  oxygen,  the  shellac 
carburetted  hydrogen.  The  perfect  combustion  of  these  gases 
gives  no  smell.  2 .  Spirits  of  wine  burnt  on  finely-powdered  nitrate 
of  strontia.  3,  Dry  nitrate  of  strontia,  5  oz.;  finely-powdered  sul- 
phur, i|-  oz. ;  chlorate  of  potash,  5  drs.  ;  sulphuret  of  antimony, 
4  drs.  Powder  the  chlorate  and  sulphuret  separately  ;  mix  on 
paper,  and  add  the  others  previously  powdered.  For  use,  mix 
some  powder  in  a  small  quantity  of  spirits  of  wine.  Should  the 
fire  burn  badly,  add  a  very  little  powdered  lampblack  or  charcoal. 
Green  or  Blue. — When  copper  is  burned  in  a  hydrogen  flame 
it  gives  a  bright  green  colour,  but  the  moment  a  little  free  chlo- 
rine is  introduced  the  colour  becomes  a  beautiful  blue. 

In  addition  to  the  above,  any  of  the  simple  preparations  of 
colours  given  under  "  Rockets  "  and  "  Roman  Candles  "  may 
be  adapted  for  burning  open. 

Roman  Candles. — The  cases  are  made  by  tightly  winding 
stout  paper  around  a  mandril  or  ruler,  the  desired  size,  and 
between  each  wind  or  roll  round  the  ruler  paste  should  be  ap- 
plied to  the  paper.  When  the  case  is  thus  made  and  wet,  it 
must  be  tied  round  the  bottom  to  close  that  aperture,  and  to 
form  a  solid  bottom  to  work  upon. 

^oioxQ filling  the  case  (which  is  the  next  process)  introduce 
a  little  clay  to  the  bottom,  thereby  forming  a  better  and  firmer 
bottom.  Next  add  a  little  coarse  powder,  and  cover  it  with  paper. 
It  is  now  ready  to  receive  the  composition  which  is  thus  made : 
— Mealed  powder,  \  lb. ;  saltpetre,  2^  lb.  ;  sulphur,  ^  lb.;  glass 
dust,  \  lb.  This  should  fill  about  a  sixth,  and  be  covered 
in  about  two-thirds  of  its  diameter.  Then  add  corn  powder  and 
a  ball  smaller  than  the  diameter.  More  composition  should  now 
be  added,  until  the  case  is  one-third  full;  then  paper,  powder, 
and  ball  again  until  it  is  finished,  the  top  being  composition. 
Paste  touch-paper  round  the  hole  and  add  a  priming  of  powder. 
The  best  way  of  exhibiting  these  Roman  candles  is  to  place 
them  in  rows  on  a  stand,  some  perpendicular,  others  declining 
in  divers  angles,  that  the  balls  may  be  projected  to  various  dis- 
tances, and  produce  a  more  splendid  effect.  The  greatest  de- 
clension should  not  exceed  45°  or  50°. 


PYROTECHNY.  291 


Composition  for  the  Coloured  Balls. — Various  forms  are 
used,  but  the  best  is  to  make  the  composition  into  a  paste,  then 
roll  it  into  shape  (as  directed  above),  and  when  rolled  in  pul- 
verized powder  (whilst  moist)  they  are  ready  for  use.  Blue 
balls  or  stars  : — Mealed  powder,  8  oz.  ;  saltpetre,  4  oz.  ;  sul- 
phur, 2^  oz.  ;  isinglass,  2  oz.  ;  spirits  of  wine,  2  oz.  Stars  or 
balls  of  fine  colour : — Mealed  powder,  i  oz.  ;  saltpetre,  i  oz,  ; 
sulphur,  I  oz.  ;  oil  of  turpentine,  4  drs.  ;  camphor,  4  drs. 
Purple  stars : — Chlorate  of  potash,  42  parts;  saltpetre,  22^ 
parts  ;  sulphur,  22^  parts  ;  black  oxide  of  copper,  10  parts  ; 
Ethiop's  mineral,  2^  parts.  Green  stars  : — Nitrate  of  barytes, 
62^  parts  ;  sulphur,  10^  parts;  potash,  23!  parts  ;  orpiment, 
i\  parts  ;  charcoal,  i^  parts.  Yellow  stars  : — Nitrate  of  soda, 
7 4^  parts ;  sulphur,  1 9^  parts ;  charcoal,  6  parts.  Cri7nson  stars  : 
— Chlorate  of  potash,  17  parts  ;  strontian,  55  parts  ;  charcoal, 
4  parts  ;  sulphur,  1 8  parts.  They  may  be  slightly  moistened 
with  spirit.  Great  care  must  be  taken,  or  spontaneous  com- 
bustion will  take  place. 

Coloured  Stars  for  Rockets. — The  different  fires  should  al- 
ways be  made  up  wet — mixed  into  a  rather  dry  paste  with  gum- 
water  (8  oz.  of  gum  to  a  pint  is  sufficient),  and  the  stars 
pressed  into  a  little  mould,  by  which  means  they  will  do  with 
much  less  gum-water.  The  proportions  for  the  stars  have  been 
given  thus  : — Mix  meal  powder,  2  parts  ;  camphor,  i  part  ; 
sulphur,  I  part  ;  coloured  fire,  moistened  with  oil  of  turpentine, 
I  part.      Work  together  in  little  round  balls,  and  place  in  rocket. 

Sulphur  and  potash  should  never  be  rubbed  together  by 
themselves,-  but  French  polish  enough  should  be  used  to  make 
a  dough,  which  should  be  rolled  well  on  a  board  to  the  thick- 
ness of  a  quarter  of  an  inch  ;  when  dry,  the  dough  should  be 
cut  into  small  cubes.  It  is  better  to  buy  the  chlorate  of  potash 
all  ready  ground,  and  care  must  be  taken  in  mixing,  as  it  ex- 
plodes at  a  low  temperature  with  all  combustible  substances, 
and  the  stars  should  be  well  dried  in  a  tin  water-bath,  and  the 
red  stars  kept  in  a  dry  well-stopped  bottle. 

The  various  colours  are  made  in  the  following  propor- 
tions : — Red. — i.  Dry  nitrate  of  strontia,  72  parts  ;  sulphur,  20 
parts  ;  gunpowder,  6  parts  ;  coal-dust,  2  parts.  2,  Nitrate  of 
strontia,  1 6  parts ;  chlorate  of  potash,  8  parts ;  sulphur,  4 
parts  ;   charcoal  (fine),  i  part. 


292 


PYROTECHNY. 


Eockets. — Among  the  most  effective  of  fireworks  are  rockets. 
To  make  thein^  erect  a  small  monkey  machine,  two  uprights 
3  ft.  6  in.  high,  with  head  and  pulley  fixed  in  same.  A  piece 
of  beech  for  monkey,  4  lbs.  weight,  and  sliding  up  and  down 
between  uprights,  being  kept  to  its  place  by  beads  nailed  to  up- 
rights. A  ring  and  cord  are  fixed  to  monkey  to  raise  it  by  the 
pulley,  and  a  pin  or  other  contrivance  for  keeping  the  monkey 
suspended  when  required. 

The  moulds  required  for  supporting  the  cases  while  being 
rammed  are  generally  cast-brass  cylinders,  bored  to  the  exter- 
nal diameter  of  the 
case.  Use  pieces 
of  brass  tube  of  the 
proper  bore,  driven 
into  a  hollow  cylin- 
der of  beech  to 
support  it.  The  foot 
of  the  mould  is  a 
cast-brass  flange  f 
in.  thick,  with  a  solid 
cylinder  i  in.  high 
for  the  mould  to  fit 
over  and  nipple  cast 
on;  the  brass  spindle 


RAMMERS, 


is  then  screwed  into  the  nipple  and  the  whole  turned  up  in  a 
lathe  ;  finally  a  J-in.  hole  is  bored  through  the  mould  I  ft.  \ 
in.  above  the  bottom,  through  which  a  pin  fastens  the  mould  to 
the  foot  during  the  ramming. 

The  rammers  are  pieces  of  cast  bar  brass  turned  down  to  i 
1 6th  in.  less  than  the  internal  diameter  of  the  case,  and  bored 
to  fit  over  the  spindle  the  exact  size  of  same ;  the  second  ram- 
mer half  way  up  spindle,  and  the  exact  size  of  the  taper  half 
way  up  ;  the  third  rammer  to  be  short  for  the  solid  charge 
above  the  spindle.  It  is  useless  to  make  wooden  rammers, 
as  they  would  not  last  under  the  monkey  for  half-a-dozen 
cases. 

The  charges  are  introduced  with  ladles  made  of  thin  brass 
tube,  with  a  handle  driven  in  one  end  and  cut  obliquely  at  the 
other,  and  should  contain  sufficient  composition  to  rise  |  of  a 
diameter  after  ramming. 

The  internal  diameter  of  the  case  determines  the  length  and 


PYROTECHNY.  293 


proportions  of  the  spindle.  It  will  be  best  to  give  the  sizes 
of  the  cases  in  ounces  and  diameters,  i  oz.  case,  4-ioths  of 
an  inch  internal  diameter;  2  oz.  ditto,  j  in.  j  4  oz.,  7-ioths  ; 
8  oz.,  9-ioths,  and  the  thickness  of  the  paper  eases  one  quarter 
the  internal  diameter,  making  a  2  oz.  case  of  \  in.  internal  dia- 
meter "I  in.  external  ditto. 

The  rule  for  the  proportions  of  spindle.  The  length  is  4! 
times  the  internal  diameter  of  case,  thickness  at  bottom  \ 
diameter,  tapering  to  the  top  at  one  half  the  diameter  at  the 
bottom. 

The  sticks  should  be  of  clean  yellow  pine,  and  of  such  length 
that,  when  tied  on  the  rocket  charged  with  stars,  they  should 
balance  one  another  \  an  inch  from  the  mouth  of  the  case. 
The  lighter  and  longer  the  sticks  are  the  better,  but  must  be 
strong  enough  to  bear  the  great  force  of  the  fire  against  them. 
2  oz.  rockets  3  ft.  long  and  \  in.  square ;  4  oz.  ditto,  3  ft.  6  in. 
long,  and  |^  in.  x  ;|  in.;    8  oz.,  5  ft.  long,  |-  in.  x  |  in. 

Composition  for  Rockets.— One  of  the  best  compositions 
for  the  body  of  sky  rockets  is  8  parts  nitre,  3  parts  charcoal, 
and  2  parts  sulphur.  i.  For  one  or  two-ounce  rockets — i  lb. 
of  gunpowder,  2  oz.  of  charcoal,  and  i  J  oz.  of  saltpetre  ; 
powder  separately  and  mix.  2.  Two  to  three-ounce  rockets — 
to  4  oz.  of  gunpowder  add  i  oz.  of  charcoal,  or  to  9  oz.  of 
powder  add   2    oz.    of  saltpetre.     3.   Four-ounce  rockets — to 

1  lb.  of  gunpowder  add  4  oz.  of  saltpetre  and  i  oz.  of  charcoal. 
4.  Five  or  six-ounce  rockets — gunpowder,  2  lbs.  5  oz.  ;  salt- 
petre, \  lb.  ;   sulphur,  2  oz.  ;    charcoal,  6  oz.  ;   and  iron-filings, 

2  oz.  5.  Seven  or  eight-ounce  rockets — gunpowder,  17  oz.  ; 
saltpetre,  4  oz.  ;  sulphur,  3  oz.  6.  Eight  to  ten-ounce  rockets 
— gunpowder,  2  lbs.  5  oz.  ;  saltpetre,  8  oz.  ;  sulphur,  2  oz.  ; 
charcoal,  7  oz.  ;  iron-fiHngs,  3  oz.  7.  Ten  or.  twelve- ounce 
rockets — gunpowder,    i  lb.    i   oz.  ;   saltpetre,  4  oz.  ;    sulphur, 

3  J  oz.  ;  charcoal,  i  oz.  8.  Twelve  to  fourteen- ounce  rockets 
— gunpowder,  2  lbs.  4  oz.  ;  saltj>etre,  9  oz.  ;  sulphur,  3  oz.  ; 
charcoal,  5  oz.  ;  iron  filings,  3  oz.  9.  One-pound  rockets — 
gunpowder,  i  lb.  ;  charcoal,  3  oz.  ;  sulphur,  i  oz.  10.  Two- 
pound  rockets — gunpowder,  i  lb.  4  oz.  ;  saltpetre,  2  oz.  ;  char- 
coal, 3  oz.  ;  sulphur,  i  oz.  ;  iron-filings,  2  oz.  11.  Three- 
pound  rockets — gunpowder,  4  oz.  ;  saltpetre,  i  lb.  ;  sulphur, 
8i  oz.  ;  charcoal,  2  oz.      12.   For  rockets  of  the  largest  size — 


294  PYROTECHNY. 


to  8  lbs,  of  saltpetre  add  20  oz.  of  sulphur  and  44  oz.  of  char- 
coal. The  ingredients  in  each  of  these  are  to  be  separately 
powdered,  and  then  thoroughly  mixed. 

Another  variety  of  composition  is  made  thus  : — For  two- 
ounce  rockets — meal  powder,  8  oz.  ;  steel-filings,  2  oz.  ;  char- 
coal (about  as  fine  as  single  F  powder),  i  oz.,  rammed  with  8 
blows  of  monkey,  with  a  fall  of  20  in,  to  each  ladleful  of  charge. 
The  same  composition  for  a  four-ounce  rocket,  reducing  the 
blows  of  monkey  to  six.  This  is  a  very  brilliant  charge,  and 
leaves  a  fine  tail  in  the  ascent.  Eight- ounce  rockets — meal 
powder,  1 6  oz.  ;  nitre,  i  o  oz.  ;  sulphur,  2  oz.  ;  charcoal,  2  oz.  ; 
with  five  blows  of  monkey.  The  solid  charge  over  the  top  of 
spindle  should  be  i  ^  diameter. 

Purple. —  I.  Chlorate  of  potash,  2  parts;  black  oxide  of 
copper,  I  part;  sulphur,  i  part.  2.  Nitre,  25  parts;  nitrate 
of  strontia,  2  5  parts  ;  sulphur,  4  parts  ;  realgar,  2  parts  ; 
lampblack,  i  part. 

Blue. — Nitre,  6  parts  ;  sulphuret  of  antimony,  i  part ;  sul- 
phur, 2  parts  ;   lampblack,  i  part. 

Green.  —  i.  Barium  nitrate,  TJ  parts;  sulphur,  13  parts; 
potassium  oxymuriate,  5  parts  ;  metallic  arsenic,  3  parts  ;  and 
calamine,  2  parts.  2.  Nitrate  baryta,  16  parts  ;  chlorate  of 
potash,  8  parts  ;  sulphur,  4  parts  ;  sulphurs  of  antimony,  f 
part ;  charcoal,  J  part.  3.  Nitrate  of  baryta,  84  parts  ;  real- 
gar, 4  parts  ;   sulphur,  1 6  parts  ;   lampblack,  2  parts. 

Yellow. — Nitrate  of  soda,  74^  parts;  sulphur,  191- parts; 
charcoal,  6  parts. 

White. — I.  Magnesium  wire  and  chlorate  of  potash.  2. 
Nitre,  6  parts  ;  sulphur,  2  parts  ;   meal  powder,  3  parts. 

Fire-Balloon  Construction. — Procure  a  quantity  of  coloured 
tissue  paper,  some  paste  made  by  mixing  flour  with  water  till 
of  a  creamy  consistence,  and  then  boiling  it  till  thick. 
One  ounce  of  alum  to  a  quartern  of  flour  improves  the 
quality.  Purchase  about  three  feet  of  stout  wire  for  a  hoop,  a 
little  light  wire  to  suspend  the  sponge,  tow,  &c.,  saturated  with 
spirits  of  wine  or  other  light  burning  hquid.  Make  the  paper 
into  gores,  the  shape  of  which  can  be  arrived  at  by  dividing  a 
well-grown  pear  into  six  or  more  parts,  then  taking  the  rind  off 
one  of  the  parts  and  laying  it  flat.  The  greater  the  number  of 
gores   the   more   trouble,   but  the    greater  the  probability  of 


ELECTRICITY,  MAGNETISM,  ETC.  295 

symmetry.  It  is  seldom  advisable,  however,  to  have  more 
than  twelve  gores,  unless  the  balloon  is  to  be  a  very  large  one. 
Join  the  gores  in  twos  ;  first  let  them  dry,  and  then  in  fours, 
and  so  on,  never  having  two  sides  of  a  gore  wet  at  the  same 
time,  or  your  patience  may  be  tried  by  one  side  parting  whilst 
the  other  is  being  pasted.  When  all  the  gores  are  joined, 
finish  the  top  by  pasting  on  it  a  circular  piece  of  paper,  to 
which  is  attached  a  loop  of  string  or  wire  to  put  a  stick  through 
as  a  support  during  the  inflation.  Fasten  the  hoop  in  the  neck 
with  thread,  pasted  paper,  &c.  ;   light  and  suspend  the  sponge. 

Pharaoh's  Serpent. — This  curious  toy  really  constitutes  an 
interesting  chemical  experiment.  It  consists  of  a  little  cone  of 
tinfoil  about  an  inch  high.  This  cone  is  lighted  at  its  apex, 
when  there  issues  from  it  a  thick,  serpent-like  coil,  which  con- 
tinues twisting  and  increasing  in  length  to  an  almost  incredible 
extent.  This  coil  is  solid,  and  may  be  handled,  although  it  is 
very  fragile.  The  white  powder  with  which  the  cones  are  made 
consists  of  sulphocyanide  of  mercury,  which,  when  heated  to  a 
temperature  below  redness,  undergoes  decomposition,  grows  in 
size,  and  produces  a  mixture  of  mellon  (a  compound  of  carbon 
and  nitrogen),  with  a  little  sulphide  of  mercury.  It  is  yellow 
on  the  exterior,  but  black  within.  The  "  serpent "  shape,  of 
course,  results  from  the  salt  being  burnt  in  a  cone  of  tinfoil. 

Electrical  Machine,  Hqw  to  Make. — Having  procured  a 
cylinder  6^  in.  long  and  4  in,  in  diameter — cost  half-a-crown 
—you  will  require  a  stand.  Take  a  piece  of  wood  8  in,  by  7 
in.  by  |  of  an  inch  thick,  which  will  form  the  bottom  of  the 
stand.  Two  uprights  support  the  cylinder.  Let  these  be 
about  7  in.  high  by  3  in.,  and  of  the  same  thickness  as  the 
piece  forming  the  bottom,  and  let  them  each  have  a  hole  made 
in  them,  about  5^  in.  from  the  bottom,  to  admit  the  ends  of 
the  axle  of  the  cylinder  to  revolve  freely,  but  not  too  loosely 
within  them  ;  these  must  be  screwed  on  to  the  bottom  piece 
(the  cylinder  having  been  first  put  in  its  place  with  the  handle 
end  to  the  right).  The  cushion  is  made  of  wash-leather  stuffed 
with  wool,  fastened  to  a  piece  of  wood  4  in.  long  by  i^  broad 
and  I  an  inch  thick,  at  right  angles  to  another  piece,  so  that 
when  fastened  to  the  stand  it  shall  press  softly  and  evenly 
against  the  side  of  the  cylinder.  This  cushion  should  have 
attached  to  it  a  piece  of  black  silk  as  broad  as  the  cushion  is 


296 


ELECTRICITY,  MA GNE TISM, 


long,  and  of  sufficient  length  to  hang  over  the  cylinder  to  within 
i  an  inch  from  the  metallic  points  of  the  conductor.  The 
cushion  should  fix  in  a  hole  on  the  front  side,  or  the  side 
nearest  half  to  you,  when  the  handle  is  to  the  right.  When  the 
machine  is  to  be  put  in  motion,  the  cushion  is  to  be  smeared 
with  an  amalgam  which  costs  sixpence  per  oz. 

You  now  want  a  conductor.  Stick  some  (five)  pieces  of  wire, 
sharpened  at  each  end,  into  a  cylinder  of  wood  covered  with 
,tinfoil.  The  cylinder  is  to  be  4  in.  long  and  i  in.  thick, 
rounded  at  each  end,  and  fastened  at  right  angles  to  a  piece  of 
glass  rod  of  such  a  length  that  the  points  shall  touch,  and  only 
just  touch,  the  side  of  the  cylinder.  A  piece  of  wire,  with  a 
brass  ball  at  its  extremity,  is  to  be  fastened  to  one  end  of  the 

conductor, to  which 

you  apply  the  knob 

^(^  //~X  /^^\>     °^  ^^  Ley  den  jar 

you  wish  to  charge. 
Paint  your  ma- 
chine, and  every- 
thing is  ready  for 
operation. 

Electro  -  Mag- 
netic   Engine.  — 

PP,two  permanent 
magnets  ;  S,  a  bar 
of  soft  iron  covered 
with  two  coils  of 
wire,  a  left  hand 
and  a  right  hand 
coil;  MM,  two 
cups  with  mercury; 
B,  a  bar  to  move 
in  R  ;  a  rest,  with 
two  arms  to  dip 
alternately  in  MM  ;  A,  an  arm  being  moved  by  W,  the  beam; 
F,  the  flywheel ;  C,  being  stationary ;  P  and  N  the  positive 
and  negative  poles  of  a  battery.  As  soon  as  the  current  is 
set  on  S,  the  bar  of  soft  iron  is  turned  into  a  magnet,  so  that 
it  is  drawn  by  one  of  the  P  magnets  and  repelled  by  the  other, 
next  the  current  is  set  into  the  other  coil  by  the  movement  of 


AND  TELEGRAPHY. 


297 


A  and  B,  which  reverses  the  poles  of  S,  the  bar  of  soft  iron,  so 
that  it  is  drawn  by  the  magnet  that  repelled  it  before  and 
repelled  by  the  one  that  drew  it. 

Magnetic  Engine. — By  this  plan  it  will  be  seen  that  by 
enlarging  GG  and  E,  and  attaching  magnets,  greater  power 
will  be  obtained.  -When  E  is  down,  the  current  is  sent  into 
the  top  magnets  by  the  spindle  KKK,  and  drawn  up  again, 
and  vice  versa,  the  current  never  being  allowed  to  be  in  both 
top  and  bottom  magnets  at  the  same  time,  which,  if  properly 
arranged,  the  spindle  and  springs  will  prevent.  The  soft  iron, 
E,  should  be  allowed  to  approach  as  near  the  faces  of  the 


magnets  as  possible,  but  never  allowed  to  touch,  or  it  will  stick 
and  retard  speed  of  engine. 

AAA,  the  bed,  to  be  made  of  hardwood  ;  BB,  support  for 
beam  ;  CC,  the  beam  ;  D,  connecting  rods  ;  E,  soft  iron  plate 
for  magnets  to  act  upon  ;  size  according  to  number  of  magnets, 
of  course.  FF,  supports  for  magnets  ;  GG,  cross  piece  for 
top  magnets  to  be  fastened  to,  and  to  be  made  of  hardwood  ; 
H,  brass  terminal  clamps  for  the  battery  wires,  i.e.,  the  clamps 
that  are  disengaged.  Ill  represent  magnets  made  of  i-inch 
soft  iron  4  in.  long,  and  each  core  covered  with  five  layers  of 
number  16  cotton-covered  copper  wire.  K  is  the  spindle  and 
crank  motion,  to  which  is  attached  two  projections  for  making 


298  ELECTRICITY,  MAGNETISM, 

and  breaking  contact  with  the  springs  facing  them,  which  are 
shown  at  HH,  and  which  reverse  the  current  from  one  set  to 
the  other,  one  of  these  projections  touching  each  spring  at 
every  half  revolution  of  the  spindle. 

Electro-Magnetic  Engine  for  Small  Battery  Power. — A 

is  the  beam,  B  the  wheel,  C  the  pillars  for  wheel,  DE  the 
magnet,  which,  if  the  stands  be  about  6  in.  high  and  the  other 
parts  in  proportion,  should  be  about  2I  in  or  3  in.  long,  with 
soft  iron  core  \  in.  thick,  and  should  be  wrapped  with  about 
half  a  pound  of  covered  copper  wire.  This  magnet  is  fastened 
down  on  the  base,  between  the  stands,  as  shown  ;  F  is  one  of 
two  oscillating  iron  arms  made  in  one  piece  similar  to  fig.  2, 
the  distance  between  this  arm  F  and  H  must  slightly  exceed 
the  length  of  the  magnet ;  this  armature  must  be  fixed  between 
the  stands  to  oscillate  on  the  centres  K,  from  one  side  to  the 

other    of    core     of 
_^5S^^^^S5;^^._      FIG.1.  magnet  (the   mag- 

net being  fastened 
down  between  the 
two  arms),  thus  giv- 
ing motion  to  the 
lever  I,  thence  by 
means  of  the  beam 
to  the  crank  and 
wheel.  The  current 
breaker  consists  of 
two  revolving  arms 
L,  which  strike  alternately  on  the  spring  M,  two  contacts  being 
made  during  one  revolution  of  wheel.  The  breaker  action  is 
as  follows  : — Suppose  the  wheel  to  revolve  in  the  direction 
shown,  and  the  crank  to  be  at  bottom,  it  will  be  seen  on  exa- 
mination that  one  arm  of  breaker  will  touch  the  spring  M,  thus 
completing  the  circuit,  while  the  armature  F  will  be  on  the  left 
side  of  the  magnetic  core.  The  galvanic  current  now  flowing 
through  the  copper  wire  magnetizes  the  core,  which  immediately 
attracts  the  armature,  and  draws  it  downward  till  opposite  the 
core,  when  the  breaker  leaves  contact  with  the  spring,  stopping 
the  current  and  destroying  the  magnetism  (otherwise  it  would 
hold  the  armature  and  prevent  its  moving  to  either  side),  thus 
allowing  the  arm  to  complete  its  oscillation,  and  the  crank  one- 


AND  TELEGRAPHY. 


299 


half  revolution.  At  this  point  the  other  arm  of  breaker  touches 
the  spring,  the  current  again  flows,  the  former  action  is  repeated 
the  other  way,  and  the  crank  completes  the  remaining  half 
revolution.  The  wire  ends  of  magnet  are  connected  one  to  one 
terminal,  and  the  other  to  the  spring  as  shown,  while  the  other 
terminal  is  connected  to  one  of  the  pillars  of  wheel,  the  spring 
is  not  allowed  to  touch  any  conducting  part  except  the  breaker 
in  its  revolutions. 


Electro-Magnetic  Engine. — The  peculiarity  of  this  machine 
is  the  construction  of  the  electro-magnets.  BB,  fig.  i,  are  two 
hollow  wooden  cy- 
linders, and  round 
them  is  coiled  a 
great  length  of  co- 
vered copper  wire, 
No,  16.  There  are 
two  cores  of  soft 
iron,  the  one  XPX, 
which  is  fixed, 
reaches  half-way  up 
the  cylinders  BB  ; 
the  other,  KLK,  is 
movable,  and  enters 
without  friction  into 
the  cylinders.  To 
this  core  is  attached 
a  rod  R,  which,  is 
used  as  a  connect- 
ing-rod. In  this 
engine  (fig.  2)  two 
of  these  electro- 
magnets are  used, 
their  movable  cores, 
M  K,  being  suspend- 
ed from  the  working 
beam  EFG,  which 
is  prolonged  to  A,  where  a  connecting-rod,  AK,  gives  motion 
to  the  fly-wheel  by  the  crank  KL.  Now,  when  a  voltaic  cur- 
rent is  made  to  circulate  in  the  electro-magnets,  both  cores 
become   powerfully   magnetized,    and    in    opposite    directions, 


300  ELECTRICITY,  MAGNETISM, 

therefore  they  attract  each  other  ;  but  the  one  being  fixed,  the 
other  is  drawn  down,  thus  giving  motion  to  the  working  beam. 
By  sending  a  current  alternately  round  the  two  electro-mag- 
nets, the  beam  is  made  to  oscillate  at  the  point  F.  The  way 
in  which  the  current  is  so  changed  from  one  electro-magnet  to 
the  other  is  thus  : — The  axis  of  the  fly-wheel  carries  an  eccen- 
tric, which  gives  a  reciprocating  motion  to  a  slide  //,  of  ivory, 
covered  in  a  part  of  its  length  by  a  brass  strip  h ;  3.  copper 
wire,  c,  is  bent  so  as  to  press  continually  on  the  brass  strip, 
and  which  wire  also  is  in  communication  with  the  zinc  of  the 
battery  by  the  wirej/.  Two  other  wires,  ac,  press  on  the  slide 
//,  and  communicate,  one  with  the  magnet  p  by  the  wire  <?,  and 
the  other  with  the  magnet  B  by  the  wire  g.  The  recipro- 
cating motion  of  the  slide  brings  the  strip,  a,  alternately 
under  the  wires  a  and  c^  so  that  the  current  is  made  to  flow 
from  the  battery  by  the  wire  f,  either  round  the  coils  B,  and 
by  ghby  to  the  zinc,  or  round  the  coils  P  and  by  eahby  to  the 
zinc. 

Simple  Electrical  Machine. — This  consists  of  a  disc  of 
strong  paper,  30  centimetres  in  diameter,  mounted  on  an  axis 
made  of  glass  tube  or  some  other  nonconducting  material,  and 
capable  of  being  made  to  revolve  about  fifteen. times  in  a  second 
by  means  of  wheels,  an  endless  band,  and  a  handle.  In  front 
of  the  disc  are  two  metallic  rods,  having  pointed  extremities, 
which  are  perpendicular  to  the  disc,  being  turned  towards  it, 
and  at  equal  distances  from  its  centre.  The  remaining  por- 
tions of  the  rods  are  bent  perpendicularly,  one  up  and  the 
other  down,  so  that  the  metallic  balls  on  their  other  extremities 
may  be  at  an  adjustable  distance  from  each  other.  The  ap- 
paratus is  charged  by  placing  a  sheet  of  paper  that  has  been 
well  dried  at  the  fire,  and  electrified  by  friction,  very  near,  but 
not  in  contact  with  the  disc,  opposite  to  one  of  the  pointed 
collectors,  but  not  at  the  same  side  of  the  disc.  On  turning 
the  machine,  a  luminous  jet  will  pass  between  the  balls.  If 
the  disc  is  covered  with  gum  lac,  and  sheets  of  paper  oppo- 
sitely electrified  are  placed  opposite  the  points  of  the  collectors 
— one  sheet  being  opposite  to  each  collector— the  intensity 
and  duration  of  the  effects  obtained  will  be  greatly  increased. 
When  the  experiment  is  carefully  made,  sparks,  five  centimetres 
in  length,  will  pass  between  the  balls,  and  a  Leyden  jar,  the 


AND  TELEGRAPHY. 


301 


coatings  of  which  are  connected  respectively  with  the  latter, 
will  be  charged  with  great  rapidity. 

Constant  and  Cheap  Battery. — For  telegraph  purposes 
there  are  two  batteries  which  possess  these  qualities  in  a  high 
degree.  The  first  is  Mr  C.  V.  Walker's  platinized  carbon 
battery,  and  a  modification  of  DanielFs.  Mr  Walker's  is  much 
used  for  railway  telegraphs.  In  constructing  it,  it  is  best  to 
have  the  graphite  plate  about  2  in.  higher  than  the  jars,  and 
the  connecting  stips  of  copper  should  be  well  tinned  and  care- 
fully riveted  as  near  as  possible  to  the  tops  of  the  carbons,  and 
then  well  coated  with  shellac  varnish  ;  this  prevents  sulphate 
of  copper  falling  into  the  cells. 

The  second  batteiy  referred  to  is  as  follows  : — i  is  a  flat 
copper  cell,  having  a  piece  of  leather  secured  between  two 
sheets  of  perforated  copper  on  one  side ;  2,  side  view  of  the 
same  cell ;  «,  cop- 


^F 


•^^^ 


COPPER   CE.U. 


-■ 

per  cell ;  b^  b,  per- 
forated copper;  c, 
leather ;  3,  a  cell 
of  the  battery  com- 
plete. The  whole 
of  the  outside  of  the 
copper  cell  should  ' 
be  well  varnished,  and  the  perforated  side  placed  opposite  a 
piece  of  very  stout  unamalgamated  zinc  in  a  stoneware  or  other 
jar.  The  outer  cell  is  merely  charged  with  water,  and  the 
copper  one  filled  with  crushed  sulphate  of  copper  moistened 
with  water.  It  is  obvious  that  several  cells  of  this  battery  are 
required  for  a  telegraph  owing  to  its  feeble  intensity,  but  we 
are  informed  it  remains  constant  between  twelve  and  eighteen 
months. 

Flower-Pot  Battery  for  Electrotyping. —  Common  red 
flower-pots  will  answer  the  purpose  of  porous  batter)^  cells. 
Wood  diaphragms,  ox-gullet,  brown  paper,  prepared  canvas, 
&c.,  have  all  some  fatal  objection,  which  precludes  their  use 
where  long  and  constant  action  is  desirable.  The  form  of 
action  used  with  success  is  a  modification  of  Daniel's,  wherein 
the  common  red  flower-pot  is  made  to  do  duty  as  a  porous 
vessel,  and,  when  properly  selected  and  prepared,  it  answers 
the  purpose  exceedingly  well.     Other  advantages  of  this  battery 


302 


EL  EC  TRICITY,  MA  GNE  TISM, 


are,  that  nitric  and  other  acid  fumes  are  dispensed  with  ;  it  is 
the  least  costly  to  construct,  no  amalgamation  required,  and  is 
easy  to  manage  in  the  hands  of  an  amateur  or  inexperienced 
person. 


P  R  Ijfl  R  RY     BATTE  R  Y 

eoiiPECi<5n  n   A   0 


SECONDKRY  BATTERY 


Electric  Battery. — It  is  not  necessary  that  the  plates  of 
zinc  and  lead  be  rolled  up  together,  provided  the  battery  jar  is 
large  enough  to  admit  the  plan.  You  cannot  roll  up  amalga- 
mated zinc  plates  in  consequence  of  their  brittleness.  A  is  the 
primary  battery,  B  the  induction  coil,  C  the  secondary  battery, 
D,  stand  for  the  coil,  showing  the  ends  of  the  wire  connected 
to  the  binding-screw  E,  on  the  one  side,  and  the  other  end 
connected  with  the  spring  of  the  contact-breaker  F.  The  other 
portion  of  the  contact-breaker  G  is  connected  to  the  binding- 
screw  H.      The  zinc  of  the  secondary  battery  is  connected  to 

the  binding-screw 
H,  and  the  lead 
connected  to  the 
primary  coil  of  wire 
as  shown  at  I.  The 
connections  from 
the  primary  battery 
are  from  zinc  to  H, 
and  copper  to  E. 
You  will  now  be  able  to  understand  the  arrangement,  as  there 
is  nothing  very  comphcated  in  it.  J  and  K  are  wires  leading 
from  the  secondary  battery  for  experiments.  If  any  other  form 
of  coil  be  used,  the  same  plan  of  connections  must  be  adhered 
to.  When  setting  the  machine  in  operation  the  screw  of  the 
contact-breaker  must  be  brought  in  contact  with  the  spring 
portion,  and  as  long  as  the  vibration  of  the  contact-breaker 
continues  the  operation  is  going  on.  The  peculiar  arrangement 
of  the  connections  is  made  in  this  manner,  so  that  we  may 
obtain  the  extra  or  dynamic  current,  which  is  only  produced  at 
each  break  of  the  contact-breaker.  This  extra  induced  current, 
being  in  an  opposite  direction  to  the  inducting  primary  current, 
passes  only  in  the  direction  of  secondary  battery.  The  forma- 
tion on  the  lead  of  peroxide  of  lead  by  the  decomposition  of 
the  electrolyte  causes  the  immense  power  of  these  batteries. 
Two  plates  of  platinum  may  be  used  even  in  the  place  of  lead 
and   zinc     and    then   the   secondary   batteries   are  even  more 


AND  TELEGRAPHY. 


303 


powerful.  The  power  of  the  platinum  batteries  depends  upon 
the  formation  of  oxygen  on  one  plate  and  hydrogen  on  the 
other. 

Earth.  Batteries. — Zinc  and  coke  may  be  used  with  advan- 
tage in  the  formation  of  an  earth  battery.  To  construct  one 
of  this  description,  a  sheet  of  zinc,  about  i  ft.  square,  should 
be  buried  perpendicularly,  about  4  ft.  deep,  in  a  moist  soil,  and 
the  coke  placed  3  in.  from  and  parallel  to  the  surface  of  the 
zinc  plate.  It  matters  little  whether  the  wires  leading  from 
this  battery  be  insulated  or  not ;  the  value  of  an  earth  battery 
depends  on  the  moisture  of  the  ground  it  may  happen  to  be 
placed  in,  the  strength  of  current  diminishing  on  the  soil  be- 
coming dry,  and  increases  when  it  becomes  moist. 

A  simple  and  convenient  form  of  earth  battery  may  be 
formed  by  merely  burying  some  coke,  or  a  copperplate  in  the 
ground,  to  form  one  poje  of  the  battery,  and  the  gas  or  water- 
pipe  can  be  used  for  the  other  pole.  Either  of  the  above  forms 
of  earth  batteries  would  efficiently  work  an  electric  clock  of  the 
usual  description,  very  small  power  being  required.  Earth 
batteries  under  the  most  advantageous  circumstances  are  never 
very  powerful,  or,  to  speak  more  correctly,  they  rarely  exhibit 
much  "  quantity,"  whilst  induction  coils  can  only  be  worked 
efficiently  by  the  use  of  good  "  quantity  "  currents,  on  account 
of  the  thickness  of  the  primary  wire.  "  Smee's  "  arrangement 
of  coil,  of  about  a  pint  capacity,  would  answer.  In  the  absence 
of  information  as  to  the  gauge  and  length  of  primary  wire,  it 
would  be  well  if  different  proportions  of  exciting  solution  were 
tried,  commencing,  say,  from  i  part  sulphuric  acid  to  1 2  water, 
up  as  high  as  i  part  acid  to  6  water.  It  would  then  be  seen 
which  proportion  suited  the  coil  best.  Smee  gives  good  quality, 
is  compact,  easily  managed,  and  very  cleanly. 

Another  method. — A  coke  battery  will  be  strong  enough 
without  the  addition  of  zinc,  and  it  is  not  necessary  for  the 
wires  to  be  insulated.  In  making  the  earth  battery  there  are 
several  ways.  Dig  a  hole  about  3  ft.  deep,  and  put  two  or 
three  hundred  weight  of  coke,  and  attach  a  wire  in  any  way  to 
the  coke,  and  attach  another  to  a  gas  or  water  pipe,  and  the 
battery  will  be  complete.  Another  way  would  be,  to  attach  a 
wire  to  a  gas-pipe,  and  apother  to  a  water-pipe.  This  battery 
is  strong  enough  to  drive  an  electric  clock.      Another  battery 


304  ELECTRICITY,  MAGNETISM, 

can  be  made  by  attaching  a  wire  to  one  of  the  pipes,  and  sim- 
ply sticking  the  end  of  the  other  wire  3  or  4  in.  in  the  ground; 
but  the  first  battery  will  stand  any  length  of  time,  and  four  or 
five  electrical  clocks  have  been  worked  at  the  same  time  on 
this  battery,  and  is  much  superior  to  one  in  which  copper  and 
zinc  plates  are  used.  No  earth  battery  will  drive  a  shock 
machine. 

Artificial  Magnet. — Take  a  piece  of  round  inch  bar,  13 
in.  long,  and  bend  it  into  the  form  of  a  horse  shoe  with  the 
end  strictly  parallel;  then  get  half  a  pound  of  covered  copper 
wire,  No.  16,  and  commence  to  wind  on.  The  power  may  be 
increased  by  covering  the  iron  first  by  winding  on  strips  of  silk, 
so  that  the  surface  of  the  iron  is  protected  from  contact.  Leave 
a  free  end  of  about  3  feet  for  attachment  to  the  battery,  and 
begin  about  half  or  a  quarter  of  an  inch  from  the  end,  and 
fasten  the  first  turn  with  a  piece  of  packthread,  and  proceed  to 
wind  the  wire  on  as  closely  and  neatly  as  possible.  It  does 
not  make  any  difference  whether  it  is  coiled  to  the  right  or  the 
left,  as  it  does  not  matter  which  is  the  north  pole,  and  go  right 
round  the  magnet,  fastening  the  other  end  same  as  the  first ; 
the  coils  round  the  bend  will  be  a  little  open  at  the  outside,  or 
it  will  not  come  square  on  the  second  limb.  You  may  then 
attach  it  to  the  battery^  and  see  if  all  is  right ;  if  so,  varnish 
all  over  with  red  sealing-wax  dissolved  in  spirit,  and  it  is 
finished  ;  but  connecting  one  end  of  the  wire  will  not  be  suffi- 
cient, as  it  is  necessary  that  both  ends  of  the  wire  should  be 
attached  to  the  battery  to  complete  the  circuit,  or  the  magnetic 
influence  will  not  be  set  up.  With  this  magnet  you  can  sus- 
pend 28  lbs.,  using  a  single  pair,  zinc  and  copper,  same  as  for 
electrotype  plates  6  in.  by  3^  in.  ;  but  an  increase  in  the  bat- 
tery power  would  make  it  very  much  more  powerful. 

Electrical   Machine — Regulation   Coil. — A",  A^,  are  the 

two  ends  of  the  primary  helix ;  B^,  B^,  the  two  ends  of  the 
secondary  helix,  which  are  in  direct  communication  with  the 
two  binding  screws  to  which  the  brass  handles  for  administer- 
ing the  shock  are  attached.  D\  D^,  are  two  binding  screws 
to  which  the  battery  is  connected.  To  D^  is  soldered  one  end 
of  the  primary  helix,  but  between  the  other  end  and  D'  the 
break  must  be  fixed.  A  glance  at  the  diagram  will  show  the 
manner  in  which  this  is  done.     The  brass  tube  used  in  some 


AND  TELEGRAPHY. 


305 


coils  for  regulating  the  shock  does  so  by  shutting  off  the  mag- 
netism of  the  core  of  iron  wires,  or  rather  by  preventing  the 
primary  helix  from  inducing  magnetism  in  the  bundle  of  wires ; 
and  it  effects  its  purpose  nearly  as  well  as  the  drawing  out  of 
the  bundle;  for  brass,  although  an  excellent  conductor  of  elec- 
tricity, presents  a  most  effectual  barrier  to  magnetism,  as  may 
be  proved  by  interposing  a  piece  of  plate  brass  between  a  per- 
manent magnet  and  its  keeper,  when  the  magnet  will  be  found 
to  attract  but  very 
slightly.  For  medi- 
cal purposes  the 
current  should  not 
flow  only  in  one 
direction.  Copper 
in  combination  with 
zinc  does  not  evolve 
nearly  so  much  elec- 
tricity as  platinized  silver,  but  a  sheet  of  platinized  iron  will 
answer  nearly  as  well.  To  platinize  the  iron,  first  clean  it  well, 
and  then  pour  over  it  a  solution  of  platinum  in  nitro-muriatic 
acid,  which  will  cover  the  iron  with  a  black  precipitate,  which 
is  platinum  in  a  state  of  very  fine  division.  The  iron  must 
then  be  well  washed  in  clean  water.  Varnishing  the  surfaces 
of  the  zinc,  which  does  not  face  the  platinized  silver  or  iron 
plate,  must  in  a  measure  save  the  zinc,  and  not  prove  detri- 
mental to  the  power 
of  the  battery.  To 
regulate,  coil  gradu- 
ally by  means  of  a 
series  of  brass  wires 
let  into  the  stand, 
wind  on  the  prim- 
ary wire  in  the  or- 
dinary way,  and 
bring  out  the  ends 

from  the  secondary.  Before  commencing  to  wind  the  secondary 
wire,  bring  out  the  end  a^  which  will  subsequently  have  to  be 
soldered  to  the  terminal  b.  Now  lay  on  three  layers,  and  with- 
out breaking  the  wire  rub  off  a  portion  of  the  cotton  or  silk 
covering,  and  solder  to  the  exposed  part  the  wire  d,  which  must 
be  brought  through  the  cheek  of  the  coil,  and  will  be  afterwards 

U 


3o6  ELECTRICITY,  MAGNETISM, 

soldered  to  the  brass  knob  i.  Next  wind  two  more  layers  on, 
and  repeat  the  above  process,  bringing  out  another  wire  e^ 
which  will  have  to  be  connected  with  the  knob  2  ;  and  continue 
winding  and  bringing  a  wire  out  every  two  layers  until  the  coil 
is  full.  In  the  coil  represented  there  would  be  eleven  layers  of 
secondary  wire.  The  other  secondary  terminal,  c,  is  connected 
with  the  sliding  arm/.  It  will  now  be  seen  that,  by  turning 
the  handle  to  i,  but  three  layers  of  wire  are  in  use ;  at  2  there 
are  five,  and  so  on,  until  at  5  the  current  circulates  through  the 
entire  number  of  layers,  and  consequently  the  full  power  of  the 
coil  is  obtained. 

Amalgam  Pad. —  Take  a  piece  of  red  leather  4  in.  or  5  in. 
square,  and  spread  on  the  middle  of  the  rough  side  a  small 
quantity  of  amalgam,  to  which  has  been  added  about  i-6th  its 
bulk  of  tallow.  They  should  be  well  blended  together,  and  all 
the  mercury  that  can  should  be  pressed  out.  If  this  pad  is 
kept  dry  and  free  from  dust,  it  will  answer  for  a  very  long  time. 
To  excite  the  machine,  first  remove  all  dust  from  the  cylinder 
and  stand  with  a  warm  dry  cloth.  Then  turn  back  the  silk 
flap  of  the  rubber,  lay  the  amalgam  side  of  the  above  pad  on 
the  top  of  the  cylinder,  holding  it  in  its  place  with  a  shght 
pressure  with  one  hand  while  turning  the  machine  with  the 
other,  and  it  will  soon  speak  for  itself.  This  will  be  a  much 
cleaner  and  quicker  mode  than  putting  the  amalgam  on  the 
rubber. 

Condenser  for  Rhumkorff. — Take  a  sheet  of  varnished 
cartridge  paper,  12  in.  by  8  in.,  or  larger  if  required,  and  lay 

on  it  a  sheet  of  tin-foil  1 1  in.  by  7 
in.,  to  allow  half  an  inch  margin  all 
round  ;  then  at  one  corner  lay  a 
slip  of  foil  3  in.  by  i  in.  to  serve 
for  a  connection,  lay  over  that  an- 
other sheet  of  varnished  paper, 
then  a  sheet  of  tin-foil  and  a  strip 
of  foil  in  the  opposite  corner,  and 
so  continue  building  it  up,  being 
careful  not  to  put  two  strips  of  foil  following  in  the  same 
corner,  but  alternately,  first  in  one,  and  then  in  the  other,  so  as 
to  connect  together  eveiy  other  sheet.  The  condenser  for  the 
Rhumkorff  consists  of  50  sheets  so  put  together,  enclosed  in  a 


AND  TELEGRAPHY. 


307 


box  for  safety.  The  manner  of  connecting  the  condenser  with 
the  break  of  the  coil  may  be  seen  in  the  annexed  diagram. 
The  condensers  are  generally  placed 
underneath  the  coil ;  but  that  the 
manner  of  connecting  them  may  be 
the  more  easily  understood  they  are 
drawn  at  the  side.  In  those  coils 
the  primary  wire  is  laid  on  in 
separate  layers,  with  all  the  ends 
brought  out,  and  so  that  by  connect- 
ing the  handle  with  the  first  piece  of 
brass,  the  battery  current  passes  only  through  the  first  layer, 
thus  magnetizing  the  iron  core  but  little,  and  rendering  it 
capable  of  inducing 


but  a  weak  current 
in  the  secondary 
wire ;  but  as  the 
handle  is  moved  on- 
wards each  succes- 
sive piece  of  brass 
connects  one  more  layer  of  primary  wire,  until  at  the  last  all 
the  layers  are  connected,  and  the  core  becom.es,  when  the  cur- 
rent passes,  highly 
magnetized,  and 
capable  of  inducing 
a  strong  secondary 
current. 

Another  machine 
for  covering  wire 
with  cotton,  silk, 
&c.,  is  made  en- 
tirely of  deal.  A  is 
a  tube  for  carrying 
the  wire  through; 
B  is  a  wood  disc, 
which  can  be  glued 
on  A,  carrying  one 
or  any  number  of 
reels;  B,the  cover- 
ing material,  which 
is  passed  through  the  disc  and  a  wire  eye,  and  on  to  the  wire 


3o8 


ELECTRICITY,  MA  ONE  TISM, 


to  be  covered.    By  turning  the  crank  with  one  hand,  and  drawing 
out  wire  with  the  other,  any  length  of  wire  can  be  rapidly  covered. 

A  third  machine 
for  use  with  cotton 
is  thus  made  : — A 
is  the  handle  for 
driving;  B,  the  driv- 
ing strap;  C,  the  un- 
covered wire  on  the 
reel;  D,J-inch  tube 
conductor  ;  E,  bob- 
bin table  with  cotton 
bobbins  mounted  ; 
F,  round  zinc  table, 
with  holes  corre- 
sponding to  number 
of  bobbins;  G  is  the 
receiver  for  the  co- 
vered wire.  The 
box  containing  the 
whole  is  of  three- 
quarter  stuff,  and  is 
3  feet  by  li  feet. 

Another  plan  is 
thus  described  : — 
AA,  sole  of  machine 
made  of  wood,  into 
only  one  of  which  is 
shown.  They  are 
placed  about  3  in. 
apart.  C,  upright 
frame,  for  carrying 
shaft  D  and  tube 
E  ;  FF,  two  rollers 
for  drawing  through 
wire  as  it  is  covered; 
the  top  roller  is 
made  of  lead,  so  as 
to  give  pressure  to 
the  wire  to  take  it 
hollow  spindle   through  which  the  wire 


■hich  are  mortized  the  two  uprights   BB, 


hrouGrh 


AND  TELEGRAPH\.  309 

passes;  GG,  speer-wheel,  and  pinion  for  driving  hollow  spindle 
and  bobbin  ;  HI,  bracket  for  carrying  end  of  hollow  spindle  ; 
I,  endless  screw  for  working  the  pulley-wheel  O,  fixed  on  the 
outer  end  of  the  under  roller  F  ;  R,  support  for  steadying  the 
wire  as  it  passes  through  the  spindle  E  ;  H,  bobbin  containing 
the  threads  for  covering  the  wire  ;  L  is  a  small  eye,  fixed  into 
the  frame  that  carries  the  bobbin,  through  which  the  thread 
passes  on  to  the  wire.  In  using  the  machine,  wire  to  be 
covered  is  held  by  the  hands,  and  kept  stretched  as  it  is  drawn 
through  by  the  two  rollers;  another  pair  of  rollers  might  be 
applied  to  keep  the  wire  stretched  the  same  as  the  drawing 
rollers.  The  speeds  of  the  machine  are  as  follows,  viz.  : — 
Large  wheel  60  teeth,  pinion  1 5  teeth,  drawing  screw  6  teeth 
to  the  inch,  pulley  for  do.  3  5  in.  diameter,  drawing  rollers  3  in. 
diameter. 

Electro-Magnetic  Clocks. — AA  is  a  mahogany  case,  with 
a  glass  front ;  B  is  a  metal  bracket  fixed  to  the  back  of  the  case, 
to  which  the  pendulum  D  is  suspended;  NS  are  permanent  steel 
magnets,  fixed  to  the  sides  of  the  case  in  such  a  manner  that 
the  pendulum-ball  D  can  vibrate  freely  between  the  poles 
of  each  magnet.  The  magnets  are  placed  so  that  the  poles 
of  dissimilar  names  face  each  other.  E  is  a  small  platinum 
ball,  affixed  to  a  brass  stem,  free  to  move  to  one  side  or  the 
other,  being  fastened  to  a  light  spindle  carried  by  the  pendulum- 
rod  at  H.  The  plate  of  copper,  F,  is  deposited  in  the  moist 
earth,  from  which  a  wire,  C,  leads  to  the  bracket  B.  The  plate 
of  zinc,  G,  is  likewise  deposited  in  the  earth,  and  its  wire  leads 
to  the  piece  of  metal  I.  To  the  lower  end  of  the  suspension 
spring  of  the  pendulum  is  attached  a  wire  coated  with  silk.  It 
is  let  down  the  back  of  the  rod,  which  is  wood,  and  then  coiled 
longitudinally  in  many  convolutions  around  the  edge  of  the 
pendulum-ball  in  a  groove  previously  made  for  that  purpose. 

It  is  then  taken  up  the  back  of  the  rod,  and  terminates  in 
the  bearings  of  the  spindle  H.  The  action  of  the  apparatus 
may  be  explained  thus  : — A  constant  and  uniform  current  of 
electricity  would  be  established,  and  would  pass  through  the 
earth,  the  plates,  and  wires  in  the  direction  of  the  arrows,  so 
long  as  the  platinum  ball  E  rests  on  the  platinum  pin  project- 
ing from  the  metal  I.  But  if  the  pendulum  is  put  in  motion, 
suppose  that,  first,  it  were  drawn  aside  until  the  ball  D  should 


3IO 


ELE  CTRICITY,  MA  GNE  TISM, 


be  between  the  poles  of  the  right-hand  magnet,  the  point  H 
being  now  farther  to  the  right  than  the  ball  E,  the  latter  would 
fall  to  the  left  and  rest  on  the  pin  K,  until  the  pendulum  took 
its  vibration  to  the  left,  when  the  ball  E  would  fall  to  the  right ; 
and  so  on  continually,  the  action  being  produced  by  the  change 
of  the  centre  of  gravitation  at  each  vibration  of  the  pendulum. 
This  action  of  the  ball  E  lets  on  and  cuts  off  the  flow  of  elec- 


tricity at  or  near  the  extreme  ends  of  the  pendulum  vibrations, 
so  that  the  convolving  wire  of  the  pendulum-ball  is  attracted 
and  repelled  by  the  magnets  at  the  proper  points  of  its  vibra- 
tions, and  thus  a  continual  motion  is  kept  up  for  an  indefinite 
period  of  time.  No  explanation  is  needed  of  the  remaining 
portion  of  the  clock. 


AND  TELEGRAPHY. 


311 


Cheap  Electric  Bell. — This  will  work  about  25  yards  awa> 


Total  cost,  3s.  6d.     A,  bell ; 


from  one  small  Daniell's  cell 
B,  a  small  block  of  wood 
upon  which  the  bell  and 
magnet  are  placed  ;  C,  two 
binding-screws  ;  D,  a  quarter 
of  a  pound  of  copper-covered 
wire,  No.  16,  for  magnet; 
E,  clock-spring  for  hammer. 


Galvanometer.  —  Fig.  i 
represents  the  machine  when 
complete  ;  fig.  2  the  coils  and 
needle,  made  of  hardened 
steel  magnetized  ;  fig.  3  the 
needle  and  finger  ;  fig.  4  the 
skeleton   coil-boxes,  covered  Avith  ten  lavers  of  No. 


30  silk- 


covered  c  opper  wire,   for  intensity  purposes,  but  for   quantity 
they  should  be  wound  with  four  lavers  each  of  No.  16  cotton- 


312 


EL  EC  TRTCITY,  MA  GNE  TISM, 


covered  wire.  Figs.  5,  6,  7,  should  be  made  of  ivory,  brass, 
or  bone,  and  when  put  together  they  will  form  the  coil-box  or 
frame,  fig.  4,  ready  for  winding  on  the  wire.  If  the  boxes  are 
made  of  brass,  thev  should  be  varnished  with  shellac  varnish, 


shellac  and  naphtha.  The  wire  can  be  varnished  when 
wrapped  on  the  boxes,  but  the  operator  must  be  careful  to 
wind  the  wire  on  both  boxes,  in  the  same  direction,  or  he 
will  not  obtain  any  good  effect.     The  two  inside  wires  should 


AND  TELEGRAPHY. 


313 


be  joined  together  as  at   C,  and  the  outer  wires  to  the  ter- 
minals on  the  case. 


EIC    6 


FIC    7 


f^^s^ 


Rotating  Magnet. — The  following  is  the  most  simple  form  : 
— N,  S,  are  the  poles  of  a  horse-shoe  magnet  fixed  on  a  stand, 
W  ;  a  b\s  2,  wooden  cup  for  mercury,  divided  into  two  parts, 
a  and  b ;  «  is  connected  to  one  end,   and  b  to  the  other,  of  a 


single-cell  battery.  C  is  the  electro-magnet,  consisting  of  a 
small  bar  of  soft  iron,  surrounded  at  its  ends  with  a  continuous 
coil  of  stout  copper  wire,  the  two  terminations  of  the  wire  dip- 


SH 


ELECTRICITY,  MAGNETISM, 


ping  into  the  mercury.  The  electro-magnet  is  supported  on  a 
central  vertical  axis,  which  passes  through  a  collar,  and  termi- 
nates in  a  point,  resting  in  a  small  agate  cup,  so  that  the 
electro-magnet  is  free  to  move  in  a  horizontal  plane. 

Mounting  a  Magnetized  Needle. — Having  your  needle 
magnetized,  cut  a  piece  of  cork  cylindrical  of  the  following 
dimensions  : — Height  \  in.,  diameter  \  in. ;  push  the  needle 
through  the  cork  near  the  top,  and  in  the  bottom  of  the  cork 

insert  a  part  of  another  needle, 
leaving  the  point  projecting  \ 
in.  Balance  this  on  the  top  of 
a  piece  of  glass  rod  by  inserting 
pins  loaded  with  small  shot  op- 
posite each  other  on  either  side 
of  the  magnetized  needle.  '  The 
glass  rod  may  be  fastened  to 
the  foot  of  a  wine-glass  by 
means  of  a  piece  of  gutta- 
percha, or  wood,  or  brass.  If 
the  cork  be  varnished  with  seal- 
ing-wax varnish,  it  will  be  im- 
proved in  appearance.  The 
annexed  figure  will  illustrate 
this  arrangement.  A,  cork ; 
B,  needle  ;  C,  loaded  pin  ;  D, 
the  point  on  which  the  whole 
is  balanced. 

Electric  Telegraphy. — The 

battery,  or  generator  of  electri- 
city, is  the  fundamental  part  of 
the  electric  telegraph.  The  two 
ends  or  extremities  of  a  battery 
wherein  electricity  is  generated 
by  chemical  action  are  termed 
poles— OTiQ  of  them  the  positive 
and  the  other  the  Jtegatlve.  From  the  former  the  current  of 
positive  electricity  issues,  and  from  the  latter  the  negative. 
Before  the  two  metals  of  which  a  battery  is  composed  are 
joined  together  no   electricity  is  evolved,  and  when  metallic 


AND  TELEGRAPHY. 


315 


connection  is  established,  the  electricity  simply  makes  a  circuit ; 
but  it  is  the  opinion  of  many  eminent  electricians  that  no  par- 
ticular portions  of  that  circuit  can  be  said  to  be  either  negative 
or  positive  to  another  portion. 

There  are  two  theories  of  the  electric  fluid — the  single  and 
the  double  fluid  theory — and  the  student,  while  adhering  to  the 
single  fluid  theory,  by  which  the  action  of  the  battery  is  gene- 
rally explained,  may  confound  the  existence  of  two  different 
electrical  tensions  in  the  conductor  forming  the  voltaic  circuit, 
with  the  idea  suggested  by  the  terms  mentioned  of  two  distinct 
currents  passing  through  this  conductor  from  each  of  the  extre- 
mities of  the  battery. 
Whichever  theory  of 
electricity  is  adopt- 
ed, the  toxrviS  positive 
and  negative  will  be 
found  equally  con- 
venient and  expres- 
sive. To  reverse  the 
direction  of  the  elec- 
tric current,  or  to 
transmit  alternate 
currents  in  reverse 
directions  along  the 
conducting  wire,  are 
expressions  not  li- 
able to  misinterpre- 
tation, if  the  words 
positive  and  negative 
are  clearly  under- 
stood. 

The  battery  most 
suitable  for  telegraph 
purposes  is  the 
"  Daniell."      These 

batteries  are  very  constant,  requiring  very  little  attention,  are 
not  offensive  in  smell,  and  furnish  a  steady,  reliable  current. 
In  making  a  "  Daniell's  battery,"  not  a  little  care  should  be 
taken  to  obtain  a  porous  cell  free  from  defect.  Two  extremes 
have  to  be  carefully  guarded  against  in  selecting  a  porous  cell ; 
for  either  it  may  be  over- fired,  baked,  or  at  too  great  a  heat, 


Daniell's  Battery.         Pole  with  a  variety  of  Insulators. 


3i6  ELECTRICITY,  MAGNETISM, 

when  it  will  not  be  sufficiently  permeable  by  liquids,  that  is,  it 
may  not  be  so  porous  as  to  permit  the  liquid  to  pass  through 
without  rupture  or  displacement  of  its  parts,  or  it  may  not  be 
sufficiently  baked,  when  any  metallic  solution  will  act  upon  and 
partly  dissolve  its  substance. 

To  prove  universal  porosity  of  a  cell,  it  is  necessary  to  ascer- 
tain whether  water  will  pass  slowly,  but  entirely,  through  every 
part  of  its  texture,  or  by  touching  it  with  the  tongue  when  the 
amount  of  dryness  produced  by  the  absorption  of  the  moisture 
will  show  the  freedom  with  which  liquids  will  pass.  The  more 
porous  the  cell  is,  the  greater  the  quantity  of  electricity  deve- 
loped, and,  therefore,  the  greater  the  quantity  of  metal  deposited, 
as  the  degree  of  deposit  is  always  in  relation  to  the  quantity  of 
electricity  generated. 

The  zinc  plates  should  be  well  amalgamated,  and  the  porous 
cell  suppHed  with  a  saturated  solution  of  sulphate  of  copper. 
Very  little  acid  should  be  added  to  the  water  in  the  cell  con- 
taining the  zinc  plate.  The  outward  vessel  is  formed  of  porce- 
lain, and  consists  of  two  battery  cells.  The  copper  element  is 
immersed  in  a  porous  vessel  containing  sulphate  of  copper. 
In  order  to  prevent  as  much  as  possible  the  copper  solution 
passing  to  the  adjacent  cell,  and  its  consequent  action  upon 
the  zinc  element,  the  porous  vessel  is  saturated  with  tallow, 
excepting  upon  a  portion  of  the  surface  which  is  directly  oppo- 
site to  the  zinc  plate.  Instead  of  a  porcelain  vessel,  battery 
cells  constructed  of  ebonite  are  also  employed  with  success. 

The  quantity  and  intensity  of  the  electricity  in  the  voltaic 
pile  are  respectively  modified  by  the  size  and  number  of  the 
plates,  and  by  the  action  of  the  intervening  liquid.  When  the 
zinc  plates  are  perfectly  clean,  pure  water  produces  certain 
electrical  effects.  These  are  considerably  modified  by  dissolv- 
ing common  salt  in  it,  or  employing  other  saline  liquids,  but 
dilute  acids  are  best  calculated  to  increase  them. 

When  the  poles  of  the  voltaic  battery  are  brought  near  to 
each  other  in  acidulated  water  or  saline  solution,  or  when  these 
Uquids  are  made  parts  of  the  electric  circuit,  so  as  to  enable 
the  electric  current  to  pass  through  them,  decomposition  ensues, 
that  is,  certain  elements  are  evolved  in  obedience  to  certain 
laws.  The  water,  which  is  a  combination  of  two  gases,  yields 
oxygen  and  hydrogen,  and  the  neutral  salts  yield  acid  and 
alkalis,      In  these  cases  the  ultimate  and  proximate  appear  at 


AND  TELEGRAPHY.  317 

the  poles  of  the  battery,  not  indiscriminately  and  indifferently, 
but  oxygen  and  acids  are  developed  at  the  positive  pole,  and 
hydrogen  and  alkaline  bases  at  the  negative  pole. 

The  intensity  of  the  electric  current  is  dependent  on  the 
energy  of  the  chemical  action  on  the  zinc,  and  the  quantity 
produced  in  a  certain  space  of  time  depends  solely  on  the 
amount  of  decomposition  produced,  or. the  weight  of  zinc  dis- 
solved in  the  cell,  in  order  to  increase  the  number  of  cells 
containing  voltaic  pairs.  The  nature  of  the  exciting  fluid 
materially  affects  the  resistance  which  is  afforded  to  the  gal- 
vanic current,  for  no  strength  of  two  fluids  conducts  the  galvanic 
power  with  equal  facility. 

In  making  a  galvanic  battery,  it  is  necessary  to  have  two 
good  conducting  substances,  separated  by  a  good  intervening 
liquid.  The  amount  of  action  which  it  will  produce  will  be 
proportionate  to  the  ready  action  of  the  liquid  on  one  substance 
and  its  inaction  on  the  other,  and  will  depend  on  the  size  and 
the  power  of  the'  battery,  but  it  is  always  lessened,  first,  by 
a  slight  resistance  which  the  metals  afford  to  the  passage  of  the 
current;  secondly,  by  the  resistance  which  the  intervening  liquid 
is  certain  to  afford,  which  is  proportionate  to  its  thickness. 

If,  instead  of  a  good  conducting  metal,  the  connection 
between  the  terminal  plates  is  made  by  any  imperfectly  con- 
ducting substance  or  any  great  length  of  wires,  then  will  also 
the  power  be  still  materially  decreased.  One  ceU,  containing 
two  metals  and  an  intervening  fluid,  provided  it  be  large,  is 
sufficient  to  produce  any  amount  of  action  where  no  resistance 
is  afforded  to  the  passage  of  the  electric  current.  These  will 
remain  inactive  while  they  do  not  touch  ;  but  as  soon  as  con- 
tact takes  place,  either  in  the  exciting  fluid  at  a  distance,  or 
through  a  fluid  of  more  easy  decomposition  than  the  exciting 
fluid  of  the  battery,  the  action  immediately  commences.  The 
contact  may  be  made  through  a  great  length  of  wire  with  the 
same  result.  In  this  case,  however,  if  the  wire  be  either  long, 
of  small  diameter,  or  of  a  metal  of  no  great  conducting  power, 
it  will  be  seen  that  the  hydrogen  evolved  from  the  negative 
metal  will  be  materially  lessened,  showing  that  an  obstacle  is 
presented  to  the  electric  fluid. 

In  constructing  a  line  of  telegraph,  some  discretion  is  neces- 
sary as  regards  the  selection  of  posts  for  the  support  of  the 
wires.      It  has  been  decided  that  it  is  far  better  to  suspend 


3i8 


ELECTRICITY,  MAGNETISM^ 


wires  than  to  bui7  them,  owing  to  the  liabiUty  of  the  insulating 
material  employed  for  the  encasement  of  subterranean  wires  to 
increase  the  expense  of  repairing  faults  ;  therefore  the  majority 
of  our  inland  wires  are  supported  on  wooden  posts  along  the 
lines  of  railways  or  canals.  The  poles  should  be  at  least  5  in. 
in  diameter  at  the  top,  and  about  1 5  feet  out  of  the  ground  and 
5  feet  in.  The  length  of  the  posts  must  necessarily  vary 
according  to  the  locahty  in  which  they  are  placed.  Young  firs 
are  generally  used  for  telegraph  service  abroad,  but  in  our 
country  English  larch  is  preferable.  In  Germany  and  America 
insulators  have  been  put  up  on  the  stems  of  living  trees,  and 

found    to     answer 
B  c  l^^^@S5N     very    well.       This 

idea  arose  from  the 
fact  that  the  sap 
ingredients  of  the 
tree  are  the  prime 
movers  in  the  rot- 
ting of  dead  wood, 
and,  in  order  to 
obviate  the  draw- 
back to  this  system, 
occasioned  through 
the  violence  with 
which  trees  .  are 
moved  in  heavy 
storms,  Lieut.-Col. 
Chauvin  construct- 
ed a  swinging  in- 
sulator. This  con- 
trivance is  hung 
upon  a  hook  free  to  swing  about  (see  engraving).  The  stalk  is 
bent  in  a  curve,  away  from  the  stem  of  the  tree,  that  when  the 
latter  is  deflected  by  wind,  the  line  wire  in  swinging  may  not 
come  into  contact  with  it,  the  hook  A,  held  in  the  loop  B  of 
bracket  C,  C .  is  twisted,  so  that  in  case  of  a  sudden  jerk  the 
line  cannot  be  thrown  upwards,  and  the  insulator  disengaged 
from  the  bracket.  The  hook  D  is  also  bent  over  the  wire  to 
prevent  the  line  jumping  out.  This  is  a  very  ingenious  con- 
trivance, and  could  be  used  with  advantage  in  America,  where 
lines   have   to  be  extended  through  forests.     The  number  of 


NS'ULATOR 


AND  TELEGRAPHY. 


319 


poles  per  mile  average  from  20  to  30.  Iron  posts  are  so 
arranged  that  they  fit  telescopically  into  each  other ;  thus  they 
offer  great  facilities  for  shipment,  and  can  also  be  conveyed 
either  by  hand  or  by  the  cheapest  mode  of  conveyance.  Being 
furnished  with  turned  and  bored  points,  they  can  easily  be 
put  together.  The  similar  portions  of  the  poles  are  inter- 
changeable. Should  a 
breakage  occur,  the  part 
which  is  destroyed  can, 
therefore,  be  easily  re- 
placed. 

The  telescopic  arrange- 
ment of  the  pole  is  also 
found  advantageous  in 
over-house  telegraphs,  as, 
after  fastening  the  wires 
to  the  insulators,  the  pole 
can  be  raised  or  lowered 
at  pleasure.  The  arrange- 
ment for  fixing  the  in- 
sulators is  admirably  con- 
trived. 

The  wire  used  for  tele- 
graph lines  is  No.  8  gauge 
iron  wire,  coated  with  zinc, 
galvanized,  in  order  to 
prevent  oxidation  or  rust. 
The  zinc  is  applied  to  the 
surface  of  the  iron  while 
in  a  state  of  fusion.  Zinc- 
coated  lines  have  been 
used  several  years.  When 
the  rain  first  falls  on  the 
zinc  covering,  an  oxide  of 
zinc  is  formed,   and  this 

oxide  being  insoluble  in  water,  a  second  fall  of  rain  cannot  dis- 
solve or  penetrate  it.  The  zinc  covering  and  the  iron  wire 
inside  are  thus  prevented  from  rusting  away. 

Insulation  is  the  next  important  matter  connected  with  the 
electric  telegraph  ;  and  although  many  forms  of  insulators, 
made  of  various  substances,  have  been  invented,  proper  insula- 


320  ELECTRICITY,  MAGNETISM, 

tion  of  our  telegraph  lines  has  not  hitherto  been  attained. 
When  the  insulators  are  clean,  and  in  dry  weather,  there  is  a 
loss  at  every  point  of  support.  In  wet  weather  the  loss  is 
increased  ;  and  when  insulation  is  imperfect,  and  heavy  showers 
of  rain  occur,  the  loss  is  often  so  great  as  to  completely  suspend 
the  working  of  the  line.  Certainly,  much  can  be  done  by  in- 
creasing the  power  of  the  batteries,  still  it  is  with  difficulty  that 
we  can  work  the  wires  in  wet  or  foggy  weather.  Glass  insu- 
lators are  covered  with  a  thin  film  of  water.  Some  electricity 
will  escape  over  every  insulator  so  covered  with  moisture  ;  in 
fact,  the  glass  becomes  a  conductor.  As  it  is  exposed  to  humi- 
dity, it  attracts  to  its  surface  the  aqueous  vapours  of  the  atmo- 
sphere ;  they  form  there  a  thin  film  of  water,  by  which  the 
electricity  passes  away.  The  first  aerial  insulator  introduced 
in  this  country  was  an  earthenware  tube  of  the  size  and  form 
of  an  t.g%^  slightly  flattened  at  the  ends.  The  wire  was  passed 
through  a  hole  in  its  longer  axis.  Porous  earthenware  and 
baked  clay  insulators  are  principally  defective,  from  the  fact 
that  the  body  is  so  porous  as  readily  and  easily  to  absorb 
moisture.  Whenever  the  glazing  is  broken  through  by  the 
wire  and  the  spike,  a  moist  communication  is  at  once  estab- 
lished, and  the  insulator  is  highly  imperfect.  An  objection 
somewhat  similar  holds  against  the  use  of  gums,  resins,  and 
other  non-conducting  substances,  less  hard  than  glass,  as  the 
wire  would  soon  wear  through,  and  touch  the  pin  upon  which 
the  insulator  rests.  The  surface  is  also  liable  to  gradual  de- 
composition or  exposure.  Varley's  insulator  is  extensively  used 
in  England.  It  consists  of  two  cups  cemented  together  with 
sulphur ;  the  outer  cup  is  provided  with  a  groove,  to  which 
the  wire  is  bound.  In  the  recess  of  the  inner  cup  a  wrought- 
iron  bolt  is  cemented,  by  which  the  insulator  is  attached  to  the 
bracket  on  the  post.  A  further  insulation  is  obtained  by  coating 
the  stalk  with  vulcanite.  The  rim  of  the  outer  cup  is  rounded 
off  inside.  The  purpose  of  this  is  to  avoid  the  sprinkling  of  the 
interior  with  rain  water,  when  a  drop  hanging  upon  the  bottom 
rim  is  blown  off  by  the  wind.  When  a  strong  current  of  air 
separates  a  drop  of  water  from  a  sharp  corner,  the  drop  is 
never  carried  bodily  off,  but  bursts  in  the  direction  of  the  current. 
With  the  form  given  to  the  rim  by  Mr  Varley,  when  a  drop  hap- 
pens to  hang  on  that  side  from  which  the  wind  comes,  it  is  driven 
a  little  way  up  between  the  two  cups,  and  does  not  burst. 


AND  TELEGRAPHY.  321 

Siemen  and  Halske's  stretching  insulator  is  shown  in  the 
diagram.  It  is  made  with  a  stronger  and  larger  cast-iron  bell 
than  the  ordinary  insulator.  The  porcelain  cup  carries  a  stalk 
with  two  notches,  through  which  the  wire  is  drawn  and  wedged 
on  each  side,  leaving  a  loop  between  them.  In  cold  weather, 
when  the  line  contracts,  this  loop  allows  the  wire  between  the 
posts  to  be  slackened,  and  also,  in  case  of  a  rupture,  gives 
sufficient  space  for  making  a  joint. 

The  subtle  agent  electricity,  that  we  see,  feel,  and  know  to 
be  moving  in  things  around  us,  is  composed  of  minute  particles 
unsusceptible  of  any  further  division,  electricity  being  in  that 
respect  analogous  to  all  other  kinds  of  matter.  The  induction 
action  starts  into  immediate  existence  on  the  slightest  disturb- 
ance of  the  normal  electricity.  Distribution  shows  us  the  wire 
of  the  electric  telegraph  under  two  perfectly  distinct  aspects. 
It  seems  always  to  have  been  constructed  for  performing  two 
different  functions  not  generally  known  to  be  separable  from 
one  another  either  in  theory  or  in  practice.  The  causation  in 
both  cases  has  been  too  profound  to  be  understood. 

In  both  cases — electrical  conduction,  as  well  as  electrical 
charge,  distinct  though  they  be  when  considered  as  results — 
there  is  in  operation  for  attaching  plus  electricity  to  neutral 
matter  a  cause  that  we  have  not  yet  made  known.  Imagine  a 
spherical  particle  of  common  matter  to  have  a  portion  of  its 
surface  occupied  by  comparatively  minute  portions  of  electricity, 
attracted  towards  its  centre  as  part  of  its  natural  electrical 
equivalent,  then  three  things  will  become  apparent.  First,  that 
the  particular  particle  of  common  matter  will  have  room  to 
receive  upon  its  surface  some  additional  number  of  electrical 
particles.  Secondly,  that  that  particle,  without  attracting  a 
larger  total  quantity  of  electricity,  can  attach  to  its  surface  an 
additional  number  of  electrical  particles  if  placed  upon  it,  be- 
cause some  part  of  every  one  that  will  be  so  placed  must  be 
nearer  to  the  common  centre  of  attraction  than  all  the  parts  of 
any  one  of  them.  Under  these  circumstances,  the  parts  that 
are  nearest  making  up  in  their  total  a  quantity  required  to 
complete  the  electrical  equivalent  will  be  held  by  attraction, 
the  remaining  parts  not  attracted  by  the  common  centre  will 
be  attached  to  the  particles  of  matter  by  the  indivisibility  of  the 
particles,  and  be  to  it  a  plus  charge.  The  third  thing  that  will 
become  apparent  is,  that  as  many  particles  of  electricity  as 

X 


322 


ELECTRICITY,  MAGNETISM, 


shall  be  so  placed  on  one  side  of  the  surface  of  a  common  par- 
ticle, in  addition  to  its  natural  equivalent,  may,  if  an  adequate 
removing  cause  be  in  operation,  be  taken  from  it  at  the  same 
or  any  other  side  without  the  particle  of  matter  losing  its  normal 
quantity. 

Apart  from  the  consideration  of  all  surrounding  circum- 
stances, the  electrical  condition  of  the  particles  of  common 
matter  just  described  may  be  the  condition  of  all  the  particles 
throughout  the  whole  substance  of  a  conductor  in  its  interior 
as  well  as  its  exterior  portions.  If  then,  in  practice,  we  find 
the  condition  to  be  at  any  time  limited  to  any  particular  part 
of  a  conductor,  we  must  conclude  that  its  locality  is  alone 
determined  by  surrounding  circumstances  for  the  time  being. 
No  conductor  can  appropriate  to  itself  absolutely  a  single  par- 
ticle of  plus  electricity,  common  matter  universally  having  had 
assigned  to  it  at  its  creation  a  particular  and  unchangeable 
quantity,  so  that  any  additional  particle  that  may  be  placed 
upon  it,  it  can  only  hold,  as  it  were,  in  trust  for  some  rightful 
owner,  on  the  conditions  called  artificial  elecU'ical  equili- 
briiifit. 

The  ai'tificial  electrical  equilibrium  is  that  state  of  matter 
which  becomes  established  whenever  plus  electricity,  exerting 
attractions  for  its  equivalent  of  common  matter  from  which  it  is 
temporarily  separated,  acts  upon  surrounding  non-conducting 
neutral  particles  virtually,  though  by  reason  of  their  insulating 
nature  not  actually  dismissing  from  them  some  of  their  natural 
electricity,  and  causing  the  same  action  to  be  propagated  to 
progressively  increasing  quantities  of  insulating  matter  until, 
by  reason  of  electrical  law  of  the  squares  of  the  quantities,  the 
intensity  becomes  so  reduced  as  to  be  insensible  on  our  most 
delicate  instruments.  This,  the  ordinary  form  of  a7'tijicial 
electrical  equilibrium,  is  sometimes  somewhat  modified  by  the 
intervention  of  neutral  conducting  matter,  which,  if  it  be  near 
enough  to  sustain  the  induction,  can  actually  as  well  as  virtu- 
ally relinquish  a  portion  of  its  own  electricity,  and  thus  promote 
the  reduction  of  intensity,  especially  if  the  electricity  relin- 
quished cannot  pass  into  earth,  from  the  surface  of  which  it 
can  act  inductively  with  an  intensity  that  may  be  regarded  as 
infinitely  small.  As  the  facilities  for  the  reduction  of  intensity 
increase,  so  will,  of  course,  the  charging  capacities  or  quantities 
of  plus  electricity,  susceptible  of  being  held  under  any  specified 


AND  TELEGRAPHY.  323 

intensity,  and,  owing  to  this  law,  if  a  conducting  surface  have 
contiguous  to  it  another  conducting  surface  communicating 
with  the  earth,  it  can  receive  upon  it  under  a  given  intensity  far 
larger  quantities  of  charge  than  when  it  is  simply  surrounded 
by  air.  Considering,  then,  that  the  distance  at  which  the  elec- 
trical attraction  may  be  acting  between  a  common  particle  and 
its  electrical  equivalent  is  shortened  by  an  accession  of  plus 
electricity,  and  that  plus  electricity  on  the  surfaces  of  common 
particles  can  have  the  intensity  of  its  attraction  reduced  to  an 
insensible  amount  by  induction,  we  can  understand  plus  charge 
to  be  both  possible  and  in  perfect  harmony  with  the  doctrine  of 
limited  electrical  attractions.  Now,  when  we  lay  an  insulated 
telegraph  wire  between  two  distant  places,  and  deliver  electricity 
continually  into  one  of  its  extremities  with  greater  rapidity  than 
it  can  find  its  way  out  of  the  further  extremity  put  to  earth,  it 
is  impossible  not  to  charge  its  surface,  and  that  charge  may 
have  an  intensity  of  action  to  any  amount  not  exceeding  the 
source  from  which  the  plus  electricity  is  delivered. 

This  is  true,  whether  the  further  end  of  the  wire  be  freely 
uninsulated  or  insulated.  We  can  surround  a  long  conductor 
with  a  cylindrical  vacuum  of  diameter  large  enough  to  put 
common  matter  beyond  the  reach  of  induction,  or  we  might 
establish  a  telegraph  wire  with  perfection  ;  for,  under  such  cir- 
cumstances, electricity  would  either  not  enter  the  wire  at  all, 
or  only  do  so  in  order  to  arrive  through  it  at  some  charging 
capacity  at  the  other  end,  capable  of  holding  it  under  an  inten- 
sity below  that  of  the  source.  At  the  best,  our  telegraph  wire 
has  a  very  similar  capacity  for  charge  derived  from  the  air 
around  it. 

And  even  the  degree  of  imperfection  is  always  necessarily 
abandoned  for  a  worse  whenever  the  circumstances  of  our 
locality  constrain  us  to  convert  naked  wires  into  "  cables  "  for 
the  purpose  of  their  "  interment"  or  submersion,  for  in  either 
of  these  cases  the  solid  insulating  material  by  which  the  wires 
are  enveloped  for  maintaining  their  charges  is  far  too  thin  to 
keep  the  external  conducting  matter  at  an  effectual  distance, 
and  thereby  preventing  it  from  dismissing  by  induction  com- 
paratively large  quantities  of  electricity  to  find  on  the  surface 
of  the  earth  or  sea  a  lower  intensity  of  charge  than  could 
otherwise  be  afforded.  The  greater  charging  capacities  thus 
occasioned  are  known  practically  to  give  rise  to  evils  of  enor- 


324  ELECTRICITY,  MAGNETISM, 

mous  magnitude,  and  of  which  every  telegraphist  is  sufficiently 
sensible. 

We  now  reach  the  laws  of  electrical  conduction  as  applied 
to  electro-telegraphy,  and  we  will  proceed  with  the  following 
simple  experiment.  Place  upon  a  large  insulated  sphere  a  plus 
charge,  and  against  it  on  either  side  an  end  of  an  insulated 
rod,  one  of  the  sides  being  of  metal  and  the  other  of  glass,  dry 
and  clean.  Part  of  the  charge  will  immediately  distribute 
itself  over  the  surface  of  the  conductor,  but  not  over  that  of  the 
non-conductor.  Remove  the  glass  rod,  and  slide  the  numerous 
parts  of  its  surface  into  contact  with  the  charged  sphere.  Then, 
upon  removing  it,  it  will  be  found  with  a  plus  charge  distributed 
upon  those  parts  of  its  surface  like  the  other  rod.  In  this  ex- 
periment, had  not  conduction  been  a  preliminary  necessity, 
charge  would  have  ensued  along  both  sides  of  the  rods  directly 
they  were  placed  with  their  extremities  against  the  charged 
s'urface  of  the  intermediate  sphere,  for  both  cylindrical  surfaces 
were  susceptible  of  charge,  as  is  proved  by  the  two  being 
ultimately  found  plus  electrical.  It  is  proved  that,  although  it 
should  be  possible  to  have  conduction  along  a  wire  without 
charge  with  the  attendant  induction,  we  cannot  have  the  reverse 
of  this,  that  is,  a  charge  on  the  wire  or  its  induction,  unless 
the  wire  has  previously  acted  in  some  way  as  an  electrical 
conductor. 

Let  us  now  endeavour  to  explain  more  minutely  the  nature 
of  electrical  conduction  along  a  telegraph  wire.  For  the  sake 
of  simplicity  of  conception,  suppose  the  insulated  wire  to  consist 
of  only  a  single  line  of  particles  of  common  matter,  and  that 
we  present  to  one  of  its  ends  a  quantity  of  plus  electricity^ 
emanating  from  a  source  maintained  at  a  given  intensity  by 
virtue  of  the  shortening  distance,  as  before  explained,  the 
common  matter  of  the  line  acting  by  ordinary  electrical  attrac- 
tions, will  attach  to  itself  the  electricity  so  presented. 

Now,  if  the  line  be  insulated  at  its  further  end,  the  elec- 
tricity will  be  held  by  it  as  a  plus  charge  under  some 
intensity,  not  exceeding  that  of  the  source  from  whence  it 
is  derived  ;  but  if,  on  the  contrary,  the  further  end  of  the  line 
be  put  to  earth,  or  other  sufficiently  large  mass  of  conducting 
matter,  surrounded  by  air,  and  the  supply  of  electricity  be 
not  too  rapid,  then  conduction  and  not  charge  will  ensue,  for 
immediately  that  a  particle  of  plus  electricity  enters  the  wire 


AND  TELEGRAPHY. 


325 


at  one  end,  another  particle  of  electricity,  natural  to  the  other 
end,  will  leave  it^ — all  the  common  matter  of  the  line  still 
possessing  its  normal  equivalent  of  electricity,  because  every 
one  of  the  common  particles  will  have  acquired  an  electrical 
particle  from  its  neighbour,  situate  between  itself  and  the 
source  of  the  plus  charge.  It  may  be  that  each  of  the  common 
particles  in  the  conducting  line  is  capable  of  so  parting  with 
two,  three,  or  some  greater  number  of  particles  of  electricity 
simultaneously,  and  in  proportion  as  it  can  do  so  will  it  be  the 
better  electrical  conductor ;  but  its  capability  in  that  respect 
must  have  a  limit,  and  instead 
of  a  single  line,  as  we  have 
supposed,  every  wire  will,  of 
course,  have  some  large  num- 
ber of  such  lines  bundled  to- 
gether proportionate  to  the 
area  of  its  sections ;  from 
which  it  follows,  all  other  con- 
ditions being  constant,  that  its 
conductivity  will  be  as  its  area 
multiplied  into  the  number  of 
electrical  particles  that  each 
common  particle  can  charge 
with  its  neighbour.  So  far, 
therefore,  as  the  wire  is  con- 
cerned, charge  and  conduction 
differ  chiefly  in  this — in  the  for- 
mer the  plus  electricity  of  the 
source  passes  from  it  to  the 
wire  to  act  from   its  surface 

with  a  diminished  intensity  on  the  surrounding  air,  and,  in 
the  latter  case,  it  is  handed  on  from  particle  to  particle  of 
the  wire  to  be  conveyed  to  some  other  conductor,  having  a 
charging  capacity  that  will  enable  it  to  do  the  same  thing; 
and  either  of  these  results  will  take  precedence  of  the  other, 
as  the  surrounding  circumstances  shall  enable  it  to  be  accom- 
panied by  the  lower  intensity.  If  the  plus  electricity  meet 
with  less  inductive  reaction  by  remaining  in  the  wire  than  by 
passing  out  of  it,  charge  will  take  precedence  of  conduction  ; 
on  the  contrary,  if  the  plus  electricity  can  pass  out  of  the 
wire  to  a  lesser  amount  of  inductive  reaction,  then  conduction 


Siemen  and  Halske's  Insulator. 


326 


ELECTRICITY,  MAGNETISM, 


will  supersede  charge,  and  therefore  it  is  that  conduction  is 
consequent  upon  uninsulation  and  charge  upon  insulation  of 
the  wire.  This  is  the  theory  of  an  eminent  electrician  of  the 
present  day. 

Alphabetical  Dial  Telegraph. — The  Voltaic  Alphabetical 
Dial  Telegraph  Instrument  was  formerly  made  by  Breguet  in 


F  IG  .  I 


three  separate  parts,  namely,  the  manipulator,  receiver,  and 
the  alarum  bell.     The  three  parts  are  now  combined   in  a 


AND  TELEGRAPHY. 


327 


compact  case.  In  fig.  i  we  have  a  view  of  the  case  open, 
showing  the  face  of  the  receiver  and  the  plate  of  the  manipu- 
lator with  the  handle.  As  will  be  seen  in  fig.  2,  another  part 
of  the  case  is  hinged,  and  is  capable  of  being  opened.     On  the 


inside  of  the  lid  of  this  part  is  screwed  the  bell,  which  is  an 
ordinary  "  Tremulo"  bell.  At  the  bottom  of  the  two  sides,  and 
at  the  back  of  the  case,  are  placed  brass  terminals,  to  which 
are  connected  the  line  wire,  the  battery  wire  (copper),  and  the 


328  ELECTRICITY,  MAGNETISM, 

earth  wire.  By  turning  the  handle  on  the  dial-plate  once 
round,  we  send,  by  means  of  a  "  cranked  "  arm  not  shown  in 
the  drawing,  thirteen  copper  currents  on  the  line,  or  half  as 
many  currents  as  there  are  signs  on  the  dial-plate ;  these, 
entering  the  instrument  at  the  distant  station,  cause  the  hand 
or  pointer  on  the  face  of  the  receiver  to  revolve  once  round,  or 
should  the  handle  at  the  sending  station  be  stopped  at  any 
letter,  the  pointer  at  the  receiving  station  will  likewise  stop  at 
the  same  letter.  A  glance  at  fig.  2  will  serve  to  show  how  this 
is  effected.  A  train  of  clockwork,  which  on  the  average  only 
requires  winding  up  once  a  week,  drives  a  common  ratchet- 
wheel  with  thirteen  teeth,  the  shaft  of  which  is  carried  through 
to  the  face  of  the  receiver,  and  on  which  the  pointer  is  placed. 
This  ratchet-wheel  is  released,  half  a  tooth  at  a  time,  by  a  light 
rod,  fitted  with  a  catch,  which  is  attracted  to  the  armature  of 
the  electro-magnet,  as  it  is  attracted  to  or  pulled  back  from  the 
poles  of  the  magnet — an  attraction  and  a  repulsion  making  two 
letters.  When  the  case  is  closed,  by  means  of  a  spring  and  a 
point  seen  at  the  left-hand  corner  of  fig.  i,  the  bell  is  put  into 
circuit,  so  that  wh^n  a  current  travels  on  the  line  the  bell  com- 
mences to  ring,  and  continues  to  do  so  until  the  arrival  of  the 
clerk,  who  opens  the  case,  and  thus  brings  the  receiver  into 
circuit.  It  is  possible  to  work  these  instruments  at  the  rate 
of  twelve  words  per  minute,  and  a  Daniell's  battery  of  twelve 
elements  is  quite  sufficient  for  a  distance  of  four  or  five 
miles. 

Simple  Electric  Telegraph. — The  base  consists  of  a  piece 
of  mahogany  8  in.  square  and  i  in.  thick,  with  a  hollow  groove 

cut  in  its  centre  2 
in.  long  and  a  half 
inch  wide.  The. 
coil  consists  of  50 
ft.  of  covered  cop- 
per wire.  No.  30 
gauge,  wound  on  a 
frame  of  card  i|  in.  long,  J  in.  broad,  |  in.  deep  in  the  open 
part ;  an  ^dge  or  flange  of  card  i\  in.  wide,  2  in.  long,  is  stuck 
to  each  side  to  keep  the  wire  in  its  place.  Now  commence 
winding  the  wire  at  the  lower  left  corner,  and  wind  from  right 
to  left.     Each  end  of  the  wire  must  be  stripped  of  the  cotton, 


wl- 

Z  .  INCHES 

1 

w-r 

1 

-  L 

^u>> 

1 

x 

1 

1/" 

AND  TELEGRAPHY. 


329 


c 


so  as  to  have  the  wire  clean  for  the  electricity  to  pass.  The 
coil  is  mounted  in  the  stand  by  inserting  the  two  lower  edges 
in  the  groOve,  so  that 
the  floor  of  the  coil  is 
level  with  the  stand. 
The  needle  is  i  in. 
long,  I- 1 2th  of  an 
inch  wide,  of  hard- 
ened and  thin  steel, 
and  fitted  with  a  brass 
cap  turned  to  a  true  cone,  to  receive  the  steel  point  on  which 
it  is  to  be  balanced.  The  needle  is  then  to  be  magnetized  by 
drawing  it  across  the  face  of  a  common  horseshoe  magnet  three 
or  four  times.  This  needle  is  now  balanced  on  a  steel  point 
3-i6ths  of  an  inch  high,  soldered  into  a  copper  slip  2  in.  long. 
Now  glue  on  the  needle  a  piece  of  glazed  letter-paper,  tapering 
from  I  in.  to  a  point,  and  2  in.  long,  at  right  angles  to  the 
magnetized  needle.  To  limit  the  vibrations  of  the  paper  index, 
drive  two  copper 
pins  in  the  base  J 
in.  away  each  side 
of  the  index.  Place 
outside  the  coil  a 
small  magnet  at 
right  angles  to  the 
coil  to  keep  the  paper  index  in  the  middle  of  the  two  pins ;  it  will 
then  appear  as  shown  in  the  last  diagram. 

Domestic  Telegraph.  —  Cut  four  pieces  of  bright  brass, 
and  join  two  by  soldering  with  a  copper  wire  4  in.  long,  as  in 
fig.  I.  Then  take  the  two  other  pieces  and  join  them  in  the 
same  manner  by  a  copper  wire  2  in.  long,  as  in  fig.  2.  The 
wire  must  be  soldered  to  one  side,  the  two  pieces  to  the  left 
or  to  the  right ;  solder  two  more  wires  ;  these  wires  are  to 
go  in  the  screw-cups  of  the  battery.  Drill  a  hole  in  the 
centre  of  each  piece  of  brass,  and  countersink  each  hole 
so  that  the  heads  of  the  screws  may  be  level ;  now  screw 
the  four  pieces  on  a  piece  of  dry  wood,  as  in  fig.  3.  The 
size  of  the  brasses  should  b^  i  in.  wide,  and  i^  in.  long. 
After  the  wires  to  convey  the  electricity  are  put  up,  and  the 
telegraph  instrument  is  at  the  top  of  the  house,  and  the  con- 


330 


MA  GNE TISM,  ELECTRICITY, 


veyance  wires,  two  in  number,  are  attached  to  each  end  of 
the  coil  of  the  instrument,  the  two  ends  at  the  bottom  are 
to  be  attached  to  two  small  handles  of  brass,  as  in  fig.  4. 
When  a  message  is  sent,  the  two  handles  are  to  be  made  to 
touch  the  right  pair  of  brasses,  if  the  index  is  meant  to  turn  to 
the  right  \  if  wanted  to  turn  to  the  left,  the  handles  are  to  be 


FIC. 

3 

1® 

J. 

CD 

® 

r- 

a> 

} 


put  on  the  left  pair.  Now  perhaps  when  you  put  the  handles 
on  the  right  pair,  the  index  will  turn  to  the  left ;  you  can 
remedy  this  by  reversing  the  battery,  z.^.,  put  the  positive  wire 
where  the  negative  was,  and  the  negative  where  the  positive 
was.  By  the  adoption  of  what  is  called  a  code  of  signals,  the 
deflections  of  a  single  index  may  be  made  to  denote  all  the 


AND  TELEGRAPHY.  331 

letters  of  the  alphabet.  The  code  for  a  single  index  instrument 
is  shown  in  the  following  diagram,  the  number  of  deflections 

*  A    B    C    D  E  F 

\  W  \\\  WW  \  w  wv 
G    H    I     K   L     M 

V   w   V  ^r  \\    I 

NO    P    Q     RS 

//  ///  ////   \\  7  y/ 

T    U  V    W  X   Y 

y//  y  y/  z  y  u  jj 

\\ 

of  the  index  to  the  right  and  left  being  made  to  indicate  the 
letters  under  which  the  marks  are  placed.  The  deflections  of 
the  symbols  for  each  letter  commence  in  the  direction  of  the 
short  marks,  and  end  with  the  long  ones.  Thus  it  will  be  seen, 
that  to  indicate  the  letter  D,  the  index  is  deflected  to  the  right 
once,  then  to  the  left  once ;  whilst  two  deflections,  beginning 
with  one  to  the  left,  and  ending  with  one  to  the  right,  make  the 
letter  R. 


INDEX 


The  entries  printed  in  Capitals  indicate  that  several  articles  relating  to 
the  subject  named  will  be  found  at  the  reference  given. 


ABC  Gas  meter,  264. 
jEolian  harp,  2  28. 
Air-engine,  38. 
Air-pumps,  39. 
Alarums,  192. 

Alley's  drilling  machine,  28. 
Alloy  for  journal  boxes,  23. 
Alphabetical  dial  telegraph,  326. 
Alum  in  safes,  250. 
Amalgam  pad,  306. 
Aniline  black  varnish,  84. 
Aniline  dyes,  266. 
Aquarium  cementing,  81. 
Aquarium,  fresh-water,  240. 
Aquarium  fountain,  244. 
Axles,  hardening,  9. 

Balance,  chemical,  251. 
Balloons,  fire,  294- 
Balloons,  varnishing,  85. 
Bancroft's  lard  oil  process,  255. 
Band-saws,  brazing,  16. 
Barometer,  simple,  78. 
Battery,  constant,  301. 
Beams,  cast-iron,  breaking  Weight, 

98. 
Bell,  electric,  311. 
Bevel-wheels,  59. 
Billiard  balls,  dyeing,  54. 
Bird-stuffing,  235. 


Bisulphide  of  tin,  10 1. 

Black  for  telescopes,  &c.,  74. 

Black  Japan  varnish,  84. 

Blacking,  261. 

Blast  engine,  106. 

Bleaching  ivory,  53. 

Bleaching  powder,  268. 

Blow-pipe,  246,  247. 

Blow-pipe  jointing,  92. 

Boats,     model,     steam     propeller, 

128. 
Boilers,  105,  106,  127,  128. 
Bone  manure,  262. 
Book  marbling  and  sprinkling,  32, 

48. 
Boring,  31. 
Boring  cork,  3. 
Boring-machine,  29. 
Bowls,  cutting  out,  53. 
Brakes,  railway,  14 1. 
Brass,  bronzing,  287. 
Brass,  casting,  93. 
Brass,  lacquering,  90. 
Brass,  melting,  92. 
Brass,  pickling,  93. 
Brass,  silvering,  278. 
Brass-soldering,  91. 
Brass  tubes,  bending,  93. 
Brazing  band-saws,  16. 
Brewer's  pitch  substitute,  88. 


334 


INDEX. 


Bright's  electric  clock,  i6o. 
Bronzing,  284. 
Brooch  stones,  cutting,  33. 
Buckles  in  sheet-iron,  98. 

Camera  lucida,  77. 

Camera  obscura,  43. 

Cameras,  dead  black,  74. 

Candles,  Roman,  290. 

Capstan-pumps,  hydraulic,  41. 

Carrier,  adjusting,  24. 

Carvings,  wooden,  protecting,  184. 

Case  hardening,  96. 

Castings,  brass,  93. 

Castings,  shrinkings,  loi. 

Cements  and  Glues,  79. 

Centre-bit,  35. 

Chemical  balance,  251. 

Chemical  Processes,  &c.,  246. 

Chimney  cowls,  187,  188. 

Chimney  lamp,  262, 

Chlorate  of  potash,  250. 

Chronometer  escapement,  157. 

Chronometer  oven,  169. 

Circle,  diameter,  1 74. 

Cisterns,  194. 

Clarifying  water,  254. 

Cleaning  paint,  185. 

Cleaning  pictures,  199. 

Cloak  peg  frame,  192. 

Clockmaking,  150. 

Clocks,  electro-magnetic,  160,  309. 

Closet  construction,  189. 

Coal  gas,  bisulphide  of  carbon,  261. 

Collodion  filter,  21 1. 

Colour  vehicle,  88. 

Colouring  maps,  198. 

Columbia  metal,  29. 

Combustion  of  oil  rags,  250. 

Composition  ornaments,  186,  282. 

Composition  pictures,  222. 

Condenser,  Rhumkorff,  306. 

Copal  varnish,  85. 

Copper,  bronzing,  286, 

Copper,  coating,  94. 

Copper,  electro-gilding,  274. 

Copper,  silvering,  278. 

Copying  ink,  259. 

Cork-boring,  3, 

Cork-springs,  42. 

Cotton  photographs,  223. 


Cotton  waste,  36. 
Cotton,  waterproofing,  270. 
Cowls,  chimney,  187,  188. 
Ci-ucibles  of  lime,  250, 
Curves,  quickening,  5. 
Cutting  glass,  175,  176. 
Cutting  microscopic  sections,  74. 
Cyanide  of  silver,  204. 
Cylinders,  Geneva,  168. 

D^mp  on  walls,  184. 

Dead-black  for  telescopes,  &c.,  74. 

Designs  on  glass,  177. 

Dials,  sun,  171,  173. 

Diameter  of  circle,  174. 

Diamonds,  polishing,  47. 

Distances,  ascertaining,  6. 

Distances,  rifle  stadia,  148. 

Domestic  telegraph,  329. 

Door  spring,  185. 

Double  photographs,  214. 

Dovetailing,  180. 

Drawing,  197. 

Drawing  camera  obscura,  43. 

Drawing  on  glass,  177. 

Drawing  spirals,  4. 

Drawing  varnishes,  84,  200. 

Drilling  glass,  27. 

Drilling-machines,   3,    26,    28,    30, 

Drills,  home  made,  32. 

Drills,  tempering,  9. 

Driving-straps,  47. 

Drowning  :  a  rescue  apparatus,  55. 

Dryers,  88. 

Dyes,  265. 

Dyeing  ivory,  54. 

Earth  batteries,  303. 

Edge  tools,  sharpening,  9. 

Electricity,  &c.,  295. 

Electric  bell,  311. 

Electric  clock,  160,  309. 

Electric  railway  signal,  135. 

Electro -gilding,  273,  274. 

Electrotyping,  270. 

Enamel,  opaque,  178. 

Enamel  for  card  photographs,  212. 

Engines,  garden,  195. 

Engines'  powers,  112. 

Engine,  rotary,  102. 


INDEX. 


335 


Engravings,   transferring    to    glass, 

177. 
Epicycloidal  wheel,  175. 
Escapement,  chronometer,  157. 
Escapement,  double-roller,  159. 
Escapement,  four-legged,  154. 
Escapement,  verge,  150. 

Fan,  fire,  ii. 

Feathering  float,  60. 

Feathers,  ostrich,  dyes,  266. 

Fictile  ivory,  202. 

Files,  renovating,  4. 

Filter,  190. 

Fire-arms,  148. 

Fire-balloons,  294. 

Fire-fan,  ii. 

Fire-p4-oofing  textile  fabrics,  270. 

Fireworks,  289. 

Fish  in  plaster  moulds,  202. 

Fixing  photographs,  217. 

Fixing  prints,  211. 

Flower-pot  battery,  301. 

Flowers   dried  in  natural   colours, 

239- 
Focussing  screen,  217. 
Fog  signals,  138. 
Fountain  for  aquarium,  244. 
Freezing  mixtures,  219. 
French  weights  and  measures,  i. 
French-polish,  86. 
Fret-saws,  14. 
Friction  polish,  88. 
Frogs  in  plaster  moulds,  202. 
Furnaces,  smelting,  loi. 

Galena  and  silver  separation,  95. 
Galvanic  battery,  317. 
Galvanometer,  311. 
Garden  engine,  196,  1 97. 
Gas-blow-pipe,  249. 
Gas  generator,  49. 
Gas,  laughing,  251. 
Gas-meter,  ABC,  264. 
Gas-pipes,  soldering,  91. 
Gas-pipes,  water  in,  265. 
Geneva  cylinders,  168. 
German  silver,  100, 
German  silver,  polishing,  94. 
Giffard  injector,  109. 
Gilding,  270. 


Glass,  175. 

Glass,  cementing,  80. 

Glass,  drawing  on,  177. 

Glass,  chimney  breakage,  263. 

Glass-cutting,  175,  176. 

Glass-designs,  177. 

Glass,  drilling,  27. 

Glass,  gilding,  274. 

Glass-globes  for  magnifying  glasses, 

218. 
Glass-plates,  photographic  cleaning, 

213. 
Glass,  soluble,  179. 
Glass,  transferring  on,  177. 
Glass,  varnishing,  84. 
Glazers  for  polishing  metals,  97. 
Glues,  79. 
Gold,  artificial,  95. 
Gold,  dissolving,  95. 
Gold,  lacquer,  89. 
Gold,  mosaic,  284. 
Gold  powder,  286. 
Gold  size,  286. 

Governor's  steam,  103,  107,  108. 
Grease,  wheel,  148. 
Grinding  pebbles,  33. 
Grinding  lenses,  60. 
Grindstones,  12. 
Gum,  postage  stamp,  82. 
Gun-barrels,  149. 
Gun-barrels,  bronzing,  287. 
Gun-cotton,  149. 
Gunpowder  force,  149. 
Gauge  for  watch  hands,  170. 
Gypsum,  201. 
Gyroscope,  68. 

Hair  springs,  reducing,  165. 

Handkerchiefs,  photographic,  223. 

Hand-press,  21. 

Harness  blacking,  261. 

Harp,  ^olian,  228. 

Hat-peg  frame,  192. 

Heights,  measuring,  5. 

Hinges  cutting,  56. 

Horology,  150. 

Hot- water  pipes'  cement,  Z2. 

House,  184. 

Huxley's  tappet-pump,  no. 

Hydraulic  capstan  pumps,  41. 

Hydraulic  ram,  37. 


336 


INDEX. 


Hydrogen  lamp,  263. 
Hyposulphite  of  Ammonia,  207. 

Indelible  pencil  writing,  199. 

Indiarubber,  261,  262. 

Indiarubber  cementing,  79. 

Incrustation  in  boilers,  105. 

Injector,  Giffard,  109. 

Inks,  250. 

Inks  for  writing  in  relief  on  zinc, 

261. 
Inlaying  with  mother  of  pearl,  96. 
Insects  for  cases,  237. 
Instantaneous  photography,  204. 
Instruments,  miscellaneous,  3. 
Instruments,  to  keep  from  rust,  78. 
Insulation,  telegraphic,  319. 
Iron,  bronzing,  287. 
Iron,  buckles  in  sheet,  98. 
Iron  solders,  91. 
Iron  stains,  removing,  186. 
Ivory,  bleaching,  53. 
Ivory,  cleaning,  54. 
Ivory,  dyeing,  54. 
Ivory,  softening,  54. 
Ivory,  fictile,  202. 

Joiners  shooting  boards,  184. 
Journal-boxes  alloy,  23. 

Kaleidoscope,  57. 

Lacquers,  88. 

Lamp,  chimney,  262. 

Lamp,  hydrogen,  263. 

Lard  oil,  refining,  255. 

Lathe,  rose  bit,  4. 

Laughing  gas,  251. 

Lead  ores,  working,  102. 

Leakage  in  smoke-box,  23. 

Leather,  cementing,  79. 

Leather  washers,  35. 

Leaves,  skeletonising,  238. 

Lenses,  cleaning,  22. 

Lenses,  grinding,  60. 

Lenses'  magnifying  power,  65. 

Life-saving  apparatus,  55. 

Lighting,  262. 

Light,   artificial,    for  photography, 

215. 
Lime-crucible,  250. 


Lime-process  in  sugar   extraction, 

257. 
Lime-water,  256. 
Linen  photographs,  223. 
Lock,  magnetic,  19, 
Locomotives,  130. 
Lubricant,  250. 

Machines,  boring,  29. 

Machines,  drilling,  26,  27,  28,  30. 

Magic  lantern  photography,  220. 

Magnesium  light,  2 1 5. 

Magnetism,  296. 

Magnetic  Lock,  19. 

Mainsprings  strength,  166. 

Manure,  bone,  262. 

Map-colouring,  198. 

Marble  imitating,  185. 

Marble,  to  remove  stains,  188. 

Marbling  books,  48. 

Marine  propulsion,  60,  65. 

Matches  without  phosphorus,  249. 

Measures,  French,  i. 

Measuring  distances,  6. 

Measuring  heights,  5, 

Meek's  watch  hand  gauge,  170. 

Mercurial  pendulum,  163. 

Mercury,  extracting,  100. 

Metals  and  metal-working,  92. 

Metals,  cementing,  80. 

Metal  glazers,  97. 

Metals,  mixed,.  99. 

Metric  system,  i. 

Micagraphy,  178. 

Microscope  hints,  76. 

Microscope,  wood  sections,  74. 

Mirrors,  silvering,  276,  278. 

Modelling,  200. 

Mosaic  gold,  284. 

Mother  of  pearl,  inlaying,  96. 

Mortar,  waterproof,  184. 

Moulding  plaster,  202. 

Moulding  small  objects,  202. 

Moulding,  to  prevent  sand  sticking, 

100. 
Music,  ^olian  harp,  228. 
Music,  violins,  230. 

Nails,    French   and    English,   wire 

hand,  26. 
Needle,  magnetised,  314. 


INDEX. 


337 


Negatives,  reproducing,  222. 
Nitrate  of  potash,  253. 
Nitrate  of  silver,  209. 
Norton's  well-pump,  45. 

Oil  for  watches,  171. 
Olive  oil,  refining,  254, 
Omnibus  register,  50. 
Organ  pipes,  gilding,  283. 
Ornaments,  composition  for,  186. 
Ostrich  feather  dyes,  266. 
Oxychloride  of  zinc,  102. 

Paint,  cleaning,  185. 
Painters'  cream,  201. 
Painting  on  glass,  177,  178. 
Paintings,  varnishing,  84. 
Paper  bronzing,  289. 
Paper  varnishing,  85. 
Paper  for  transfers,  197. 
Paper  for  tracing,  198. 
Papier-mache,  49. 
Paraffin  waterproofing,  268. 
Parchment  cleaning,  56. 
Parkes'  plastic  moulding,  202. 
Pebbles,  grinding  and  polishing,  33. 
Peet's  safety-valve,  117. 
Pencil  drawings,  preserving,  199. 
Pencil  writing,  indelible,  199. 
Pendulum,  compensating,  157. 
Pendulum,  mercurial,  163. 
Peroxide  of  nitrogen,  215. 
Perpetual  motion,  electric  clock,  160. 
Petroleum  stove,  255, 
Pewter,  99. 

Pharaoh's  serpent,  295. 
Photography,  203. 
Photographometer,  206. 
Picture-cleaning,  199. 
Picture  frames,  gilding,  279. 
Picture  frames,  making,  281. 
Picture    frames,   in   compo..    orna- 
ments, 282. 
Picture  frames,  staining,  279. 
Pillar  drilling-machine,  30. 
Pin,  new  style,  25. 
Pinion  and  rack,  174. 
Plant  preserving,  258. 
Plaster  of  Paris,  201. 
Plaster  casts,  bronzing,  284. 
Plaster  casts,  varnishing,  203. 


Plate  cleaning,  95. 
Plate  soldering,  91. 
Plateholder,  photographic,  220. 
Plating,  280, 

Plating  skeleton  leaves,  239. 
Plumbers'  solder,  91. 
Polariscope,  77. 
Polish,  French,  86. 
Polish,  friction,  88. 
Polishing  diamonds,  47. 
Polishing  pebbles,  33. 
Porcelain  cementing,  81. 
Postage-stamp  gum,  82. 
Potash,  chlorate,  250. 
Potash,  nitrate,  253. 
Power  of  engines,  112. 
Preserving  plants,  238. 
Preserving  skins,  234. 
Prince  Rupert's  drops,  257. 
Printed  cottons,  washing,  268, 
Printers'  ink,  258. 
Printing  photographs,  2 1 4. 
Prints,  fixing,  211. 
Prints,  varnishing,  200. 
Processes,  Miscellaneous,  3. 
Pumps,  air,  39. 
Pump,  tappet,  I  ID. 
Pump,  deep  well,  43. 
Putty  for  steam  joints,  83. 
Pyrotechny,  289. 

Quickening  curves,  5. 

Radii-drawing  to  inaccessible  cen- 
tres, 48. 
Rags  oily  combustion,  250. 
Railways  and  locomotives,  130. 
Rain-water,  storing,  195. 
Ram,  hydraulic,  37. 
Ratchet  wheels,  52. 
Registering  machine  for  'buses,  52. 
Retouching  photographs,  221. 
Reversing  motion  in  engines,  125. 
Rhumkorff  condenser,  306. 
Rick  cloths,  waterproofing,  270. 
Rifle  stadia  for  distances,  148. 
Rock-drilling,  27. 
Rockets,  291,  292,  293. 
Roman  candles,  290. 
Rose -bit  for  lathe,  4. 
Rotary  engine,  102. 

Y 


338 


INDEX. 


Rotating  magnet,  313. 

Rupert  drops,  25. 

Rust  on  instruments,  78. 

Sackholder,  46. 

Safes,  alum  in,  250. 

Safety-valves,   1 12,    117,  1 18,    120, 

121. 
Saw  benches,  13. 
Sawing  machine,  18. 
Saws,  band,  brazing,  16. 
Saws,  fret,  14. 
Screw-driver,  20. 
Screw-propeller,  67. 
Sealing  wax,  256. 
Semaphores,  131. 
Sharpening  edge  tools,  9. 
Shooting  boards  for  joiners,  184. 
Shrinkings  of  castings,  loi. 
Siemen      and     Halske's     insulator, 

321. 
Signals,  fog,  138. 
Signals,  railway,  130,  135,  139. 
Silk,  blue,  dye,  265,  266. 
Silk  photographs,  21 1. 
Silver  cyanide,  204. 
Silver  dial  cleaning,  168. 
Silver  in   photography,    207,    208, 

209. 
Silver,  hardness,  94. 
Silver,  separating  from  galena,  95. 
Silver,  soldering,  91. 
Silver,  German,  100. 
Silvering,  brass,  278. 
Silvering,  copper,  178. 
Silvering,  imitation,  283. 
Silvering  globes,  &c.,  276. 
Silvering  mirrors,  278. 
Skates, -wheeled,  50. 
Skeleton  leaves,  238. 
Skins,  preserving,  234. 
Slide-valve,  119,  122,  126. 
Smelting  furnace,  loi. 
Smoke-box  leakage,  23. 
Smoky  chimney,  cowl  for,  188. 
Solders  and  soldering,  90. 
Soluble  glass,  179. 
Speculum  metal,  100. 
Spirals,  4,  5. 

Spirit  blow-pipes,  246,  247. 
Spring  for  doors,  185. 


Springs,  cork,  42. 
Sprinkling  book-edges,  32. 
Stains  of  nitrate  of  silver,  217. 
Stains  on  marble,  to  remove,  188. 
Staining  wood,  182. 
Steam  engine,  102, 
Steam -joints,  cementing,  82. 
Steam-pipes,  cementing,  82. 
Steam-propeller   for    model    boats, 

128. 
Steel,  bronzing,  287. 
Steel,  gilding,  273. 
Steel,  polished,  preserving,  97. 
Steel,  soldering,  91. 
Steel  surfaces,  preservation,  98. 
Steel,  tempering,  10. 
Steel  welding  composition,  96. 
Stencil-plates,  198. 
Stereotyping,  paper  process,  25. 
Stone  cementing,  80. 
Straps,  driving,  47. 
Straw,  to  colour  black,  267, 
Stud-box  and  wrench,  23. 
Studio  photographic  design,  224. 
Stuffing  birds,  234. 
Sugar  extraction,  lime  process,  257. 
Sulphate  of  iron  preservation,  99. 
Sun-dial,  171,  173. 
Superheater  and  safety  valve,  Ii8, 
Swann's  safety  valve,  113. 
Syphon,  38. 

T-square,  protracting,  10. 

Tappet-pump,  no. 

Taps,  tempering,  9. 

Taxidermy,  234. 

Telegraphy,  314. 

Telescopes,  dead  black,  74. 

Telescopes'  stand,  73. 

Telescopes,  making,  71. 

Tempera,  186. 

Tempering  drills  and  taps,  9. 

Tempering  steel,  10. 

Tent,  photographic,  227,  228. 

Textile  fabrics,  fireproof,  270. 

Tin  bisulphide,  1 01. 

Tin  lacquer,  89. 

Tinning,  loi. 

Tinware,  solder,  91. 

Tissue-paper,  oiling,  198. 

Titanium,  German,  99. 


INDEX. 


339 


Titanium,  Spanish,  99. 
Tools,  miscellaneous,  3. 
Tools,    hardening    and    tempering, 

II. 
Tools,  sharpening,  9. 
Tortoiseshell,  polishing,  56, 
Tracing-paper,  198. 
Tracings,  cement,  80. 
Tramway  locomotives,  146. 
Transferring  on  glass,  177. 
Transfer  paper,  197. 
Tube-well  pump,  44. 
Type  metal,  99. 

Valves,  safety,  112. 

Valve,  slide,  122. 

Varnishes,  83. 

Varnishes  for  photographs,  21 6. 

Varnishes  for  prints  and  drawings, 

200. 
Varnishing  plaster  casts,  203. 
Vegetables  in  plaster  moulds,  202. 
Vellum  cleaning,  55. 
Vehicle  for  colour,  88. 
Ventilation,  190. 
Verge  escapements,  150. 
Vibration,  musical,  234. 
Vinegar,  anti-pestilential,  186, 
Violins,  home-made,  230. 
Violin  tools,  231. 
Violins,  varnishing,  87. 
Vulcanised  india-rubber,  262. 

Walls,  damp,  184. 
Walls  in  tempera,  186. 
Washers,  leather,  35. 
Washing  printed  cottons,  268. 


Waste  cotton,  36. 

Watchmaking,  150. 

Water,  clarifying,  impure,  254. 

Water  storing,  195. 

Waterproof  enamel  for  photographs, 

212. 
Waterproof  mortar,  184. 
Waterproofing,  268. 
Water-wheel,  36. 
Weapons,  hardening  and  tempering, 

II. 
Weather-glass,  78. 
Weights  and  Measures,  i. 
Welding  composition  for  steel,  96. 
Well-pumps,  43,  44. 
Wheeled  skates,  50. 
Wheel,  epicycloidal,  175. 
Wheel,  feathering  float,  60. 
Wheel  grease,  148. 
Wheels,  bevel,  59. 
White  metal,  96,  99. 
Wood,  bronzing,  288. 
Wood  carvings,  protecting,  184. 
Wood  cementing,  80. 
Wood  microscopic  sections,  74. 
Woodstaining,  182. 
Woods,  strength  of,  179. 
Wood,  varnishing,  86. 
Wood,  washed,  179. 
Woodbury  process,  214. 
Woollens'  dyes,  266, 
Wrench,  23. 
Writing  in  pencil  indelible,  199. 

Zinc,  oxy chloride,  102. 

Zinc  perforated,  varnishing,  86. 

Zinc,  writing  in,  261. 


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"  The  author  has  presented  his  views  in  a  clear  and  intelligent  manner,  and 
the  ingenuity  displayed  in  coloring  the  figures  so  as  to  present  certain  facts 
to  the  eye  forms  no  inappreciable  part  of  the  merits  of  the  work.  The  reduc- 
tion of  the  '  formulae  for  obtaining  the  strength,  volume,  and  weight  of  a  cast- 
iron  pillar  under  a  strain  of  compression,'  will  be  very  acceptable  to  those  who 
have  occasion  hereafter  to  make  investigations  involving  these  conditions,  Aa 
a  whole,  the  work  has  been  well  done." — Railroad  Gazette,  Chicago, 


Allan's  Theory  of  Arches. 

18mo.     Boards.     50  cts. 

THEOEY  OF  AECHES.     By  Prof.   W.   Allax,   formerly  of 
Washington  and  Lee  University.     Illustrated. 

"  This  little  volume  is  an  amplification  and  explanation  of  Prof.  Ranktae's 
chapters  on  this  subject. " 


4  BGIEWriFia  BOOKS  PUBLISHED  BY 

Shreve  on  Bridges  and  Roofs* 

8vo,  87  wood-cut  illustrations.    Cloth.     $5.00. 

A   TEEATISE    ON    THE   STEENGTH    OF   BEIDGES  AIN'D 

EOOFS — comprising  the  determmation  of  Algebraic  formulas 
for  Strains  in  Horizontal,  Inclined  or  Eafter,  Triangular,  Bow- 
string, Lenticular  and  other  Trusses,  from  fixed  and  moving 
loads,  with,  practical  applications  and  examples,  for  the  use  of 
Students  and  Engineers.  By  S.viruEL  H.  Shreve,  A.M.,  Civil 
Engineer. 

"  On  the  wliole,  Mr,  Shreve  has  produced  a  book  which  is  the  simplest, 
clearest,  and  at  the  same  time,  the  most  systematic  and  with  the  best  math- 
ematical reasoning  of  any  work  upon  the  same  subject  in  the  language." — 
RaUroad  Gazette. 

"  From  the  unusually  clear  language  in  which  llr.  Shreve  has  given  every 
stateriient,  the  student  wall  have  but  himself  to  blame  if  he  does  not  become 
thorough  master  of  the  subject." — London  Mining  Jonrnal. 

"  'hiv.  Shreve  has  produced  a  work  tliat  must  always  take  high  rank  as  a 
text-book,  "  ■"  *  and  no  Bridge  Engineer  should  be  v/ithout  it,  as  a 
valuable  work  of  reference,  and  one  that  will  frequently  assist  him  out  of 
difficulties." — Franklin  Institute  Journal. 


The  Kansas  Oity  Bridge « 

4to.     Cloth.     16.00 

WITH  AN  ACCOUNT  OF  THE  EEGIMEN  OF  THE  MIS- 
SOUEI  EIYEE,  and  a  description  of  the  Methods  used  for 
Founding  in  that  Eiver.  By  0.  CnANUTE,  Chief  Engineer,  and 
Geoege  MoErsox,  Assistant  Engineer.  Illustrated  with  five 
lithographic  views  and  twelve  plates  of  plans. 

Illustrations. 

Views.— -View  of  the  Kansas  City  j  tion  Works,  Pier  No.  8.  IV.  Founda- 
Bridge,  August  2,  1869.  Lowering  I  tion  Works,  Pier  No.  4.  V.  Founda- 
Oaisson  No.  1  into  position.  Caisson 
for  Pier  No.  4  brought  into  position. 
Viev/  of  Foundation  Works,  Pier  No 


tion  Works,  Pier  No.  4.     VI.  Caisson 

No.  5— Sheet  Piling  at  Pier  No.  6— 

Details  of  Dredges — Pile  Shoe — Beton 

4.     Pisr  No.  1.  I  Box.      VII.  Masonry— Draw  Protec- 


Plates. — I.  Map  showing  location 
of  Bridge.  II.  Water  Pecord— Cross 
Section  of  River — Profile  of  Crossing 
— Pontoon   Protection.      III.    Water 


tion — False  Works  between  Piers  3 
and    4.       VIII.     Floating    Derricks. 

IX,  General  Elevation — 176  feet  span. 

X.  248  feet  span.   XL  Plans  of  Draw. 


Deadener— Caisson    No.    2— Founda    I  XII.  Strain  Diao-rams 


D.  VAjST  jSrOSTBARD. 


darkens 


4to, 


Quinoy  Bridge, 

Cloth.     $7.50. 


DESCEIPTION  OF  THE  IRON  RAILWAY  Bridge  across  tlie 
Mississippi  Eiver  at  Quincy,  Illinois.  By  Thomas  Cuetis  Claeke, 
Cliief  Engineer.  Illustrated  witli  twenty-one  lithographed 
plans. 

Illustrations. 


Plates. — General  Plan  of  Missis- 
sippi River  at  Quincy,  showing  loca- 
tion of  Bridge.  II«.  G-eneral  Sections 
of  Mississippi  River  at  Qtiincy,  show- 
ing location  of  Bridge.  Tlh.  General 
Sections  of  Mississippi  River  at  Quin- 
cy, showing  location  of  Bridge.  III. 
General  Sections  of  Mississippi  River 
at  Quincy,  showing  location  of  Bridge. 
TV.  Plans  of  Masonry.  V.  Diagram 
of  Spans,  showing  the  Dimensions, 
Arrangement  of  Panels,  e  EC.  VI.  Two 
hundred  and 'fifty  feet  span,  and  de- 
tails. VII.  Three  hundred  and  sixty 
feet  Pivot  Draw.  VIII.  Details  of 
three  hundred  and  sixty  feet  Draw. 
IX.  Ice-Breakers,  Foundations  of  Piers 
and  Abutments,   Water  Table,   and 


Curve  of  Deflections.  X.  Founda- 
tions of  Pier  2,  in  Process  of  Con- 
struction. XI.  Foundations  of  Pier 
3,  and  its  Protection.  XII.  Founda- 
tions of  Pier  3,  in  Process  of  Construc- 
tion, and  Steam  Dredge.  XIII.  Foun- 
dations of  Piers  5  to  18,  in  Process 
of  Construction.  XIV.  False  Works, 
showing  Process  of  Handling  and  Set- 
ting Stone.  XV.  False  Works  for 
Raising  Iron  Work  of  Superstructure, 
XVL  Steam  Dredge  used  in  Founda- 
tions 9  to  18.  X'VII.  Single  Bucket 
Dredge  used  in  Foundations  of  Bay 
Piers.  XVin.  Saws  used  for  Cut- 
ting Piles  under  water.  XIX.  Sand 
Pump  and  Concrete  Box.  XX  Ma- 
sonry Travelling  Crane. 


Whipple  on  Bridge  Biiildingo 

Svo,  lUustrated.     Cloth.     $4.00. 

AN  ELEMENTARY  AND  PEACTICAL  TEEATISE  ON 
BEIDGE  BUILDING.  An  enlarged  and  improved  edition  of 
the  Author's  original  work.  By  S.  Whipple,  C.  E.,  Inventor  of 
the  Whipple  Bridges,  &c.  Second  Edition. 

The  design  has  been  to  develop  from  Fundamental  Principles  a  system  easy 
of  comprehension,  and  such  as  to  enable  the  attentive  reader  and  student  to 
judge  understandingly  for  himself,  as  to  the  relative  merits  of  different  plans 
and  combinations,  and  to  adopt  for  use  such  as  may  be  most  suitable  for  the 
cases  he  raay  have  to  deal  with. 

It  is  hoped  the  work  may  prove  an  appropriate  Text-Book  upon  the  subject 
treated  of,  for  the  Engineering  Student,  and  a  useful  manual  for  the  Practio- 
jLng  Engineer  and  Bridge  Builder. 


6  SCIENTIFIC  BOOKS  PUBLISHED     BT 

Stoney  on  Strains, 

Netu  and  Mevised  Edition,  with  nuinerous  illustrations. 

Royal  8vo,  664  pp.     ClotK    $12.50. 

THE  THEOEY  OE  STRAINS  IN  GIEDERS  and  Similar  Struc- 
tures, with  Observations  on  tlie  Application  of  Theory  to  Practice, 
and  Tables  of  Strength  and  other  Properties  of  Materials.  By 
BiifDON  B.  Stonet,  B.  a. 


Roebling^s  Bridges. 

Imperial  folio.     Clotli.     $25.00. 

X.ONG  AND  SHOET  SPAN  EAILWAY  BEIDGES.  By  Johx 
A.  EoEBLiE-G,  C.  E.  Illustrated  with  large  copperplate  engrav- 
ings of  plans  and  views. 

List  of  Elates 

1.  Parabolic  Truss  Railway  Bridge.  2,  3,  4,  5,  6.  Details  of  Parabolic 
Truss,  with  centre  span  500  feet  in  the  clear.  7.  Plan  and  View  of  a  Bridge 
over  the  Mississippi  River,  at  St.  Louis,  for  railway  and  common  travel.  8,  9, 
10,  11,  12.  Details  and  View  of  St.  Louis  Bridge.  13.  Railroad  Bridge  over 
the  Ohio. 


Diedrichs'  Theory  of  Strains, 

8vo.     Cloth.     $5.00. 

A  Compendium  for  the  Calculation  and  Construction  of  Bridges, 
Eoofs,  and  Cranes,  with  the  Application  of  Trigonometrical 
Notes.  Containing  the  most  comprehensive  information  in  re- 
gard to  the  Resulting  Strains  for  a  permanent  Load,  as  also  for 
a  combined  (Permanent  and  H  oiling)  Load.  In  two  sections 
adapted  to  the  requirements  of  the  present  time.  By  Jonis"  Died- 
KicHS.     Illustrated  by  numerous  plates  and  diagrams-. 

"  The  want  of  a  compact,  universal  and  popular  treatise  on  the  Construc- 
tion of  Roofs  and  Bridges — especially  one  treating  of  the  influence  of  a  varia- 
ble load — and  the  unsatisfactory  essays  of  different  authors  on  the  cubject, 
induced  me  to  prepare  this  work." 


B.   VAN  NOSTRANB, 


Jacob  on  Retaining  Wails. 

18mo.     Boards.   50  cts, 

PKAOTIOAL  DESIGNma  OP  EETAmma  WALLS.      By 
Aethue  Jacob,  A,  B. 


Campin  on  Iron  Roofs. 

Large  8vo.     Clotli.     $2.00. 

ON  THE  CONSTEUCTION  OF  lEON  EOOES.  A  Theoretical 
and  Practical  Treatise.  By  Feancis  Campin.  With  wood-cuts 
ai!jd  plates  of  Eoofs  lately  executed. 

^^  The  mathematical  formulas  are  of  an.  elementary  kind,  and  the  process 
admits  of  an  easy  extension  so  as  to  embrace  the  prominent  varieties  of  iron 
truss  bridges.  The  treatise,  though  of  a  practical  scientific  cbaracter,  may  bo 
easily  mastered  by  any  one  familiar  with  elementary  mechanics  and  plane 
trigonometry." 

HoUey's  Railway  Practice, 

1  vol  folio.    Clotli.     $12.00. 

AMEEIOAN  AND  EUEOPEAN  EAILWAY  PEAOTICE,   in 

the  Economical  Generation  of  Steam,  including  the  materials 
and  construction  of  Coal-burning  Boilers,  Combustion,  the  Yaria- 
ble  Blast,  Yaporization,  Circulation,  Super-heating,  Supplying 
and  Heating  Feed- water,  &c.,  and  the  adaptation  of  Wood  and 
Coke-burning  Engines  to  Coal-burning  ;  and  in  Permanent  Yv^ay, 
including  Eoad-bed,  Sleepers,  Eails,  Joint  Fastenings,  Street 
Eailways,  &c.,  &c.  By  Alexander  L.  Hollet,  B.  P.  With  77 
lithographed  plates. 

'•'  This  is  an  elaborate  treatise  by  one  of  our  ablest  civil  engineers,  on  the  con- 
struction and  use  of  locomotives,  -with  a  few  chapters  on  tbe  building  of  E,ail- 
roeds.  ^*"  *  *  All  these  subjects  are  treated  by  the  author,  -who  is  i 
first-class  railroad  engineer,  in  both  an  iuteUigent  and  intelligible  manner.  Tho 
facts  and  ideas  are  well  arranged,  and  presented  in  a  clear  and  simple  style, 
accompanied  by  beautiful  engravings,  and  we  presume  the  work  will  be  regard* 
ed  as  indispensable  by  all  who  are  interested  in  a  knowledge  of  the  construc- 
tion of  railroads  and  rolling  stock,  or  the  working  of  locomotives." — ScientifiG 
American, 


8  SCIENTIFIC  BOOKS  PUBLISHED  BY 

Henricrs  Skeleton  Structures. 

8vo.     Clotli.    $1.50. 

SKELETON  STEUCTUEES,  especially  in  their  Application  to 
the  building  of  Steel  and  Iron  Bridges.  By  Olaus  ^enkici. 
With  folding  plates  and  diagrams. 

By  presenting  tbese  general  examinations  on  Skeleton  Structures)  'with 
particular  application  for  Suspended  Bridges,  to  Engineers,  I  venture  to  ex- 
press the  hope  tliat  they  will  receive  these  theoretical  results  with  some  confi- 
dence, even  although  an  opportunity  is  wanting  to  compare  them  with  practi- 
cal results.  O.  H. 


Useful  Information  for  Railv/ay  Men. 

Pocket  form.    Morocco,  gilt,  |2.00. 

Compiled  by  W.  G.  Hamilto:^-,  Engineer.     Sixth    edition,  revised 
and  enlarged.     570  pages. 

"  It  embodies  many  valuable  formulae  and  recipes  useful  for  railway  men,' 
and,  indeed,  for  almost  every  class  of  persons  in  the  world.  The  '  informa- 
tion '  comprises  some  valuable  formulse  and  rules  for  the  construction  of 
boilers  and  engines,  masonry,  properties  of  steel  and  iron,  and  the  strength 
of  materials  generally." — Railroad  Oazettej  Ghicago. 


HoUey^s  Ordnance  and  Armor, 

493  Engravings.     Half  Eoan,  $10.00.     Half  Eussia,  $12.00. 

A  TEEATISE  ON  ORDNANCE  AND  AEMOE— Embracing 
Descriptions,  Discussions,  £tnd  Professional  Opinions  concerning 
the  Mateeial,  Eabricatioit,  Requirements,  Capabilities,  and  En- 
durance of  European  and  American  Guns,  for  Naval,  Sea  Coast, 
and  Iron-clad  Warfare,  and  tbeir  EiruifG,  Projectiles,  and 
Bkeech-Loading  ;  also,  Results  of  Experim-ents  against  Armor, 
from  Official  Records, -witli  an  Appendix  referring  to  Grun-Cotton, 
Hooped  Guns,  etc.,  etc.  By  Alexa^^der  L.  Holley,  B.  P.  948 
pages,  493  Engravings,  and  147  Tables  of  Results,  etc. 


1\  VAN  NOS>TRAND, 


Kirkwood  on  Filtration. 

4to.     Clotli.     $15.00. 

BEPOET  ON  THE  FILTEATION  OF  EIVEE  ¥/ATEES,  for 
tlie  Supply  of  Cities,  as  practised  in  Europe,  made  to  tlie  Board 
of  "Water  Coramissioners  of  the  City  of  St.  Louis.  By  James  P. 
KiEKWooD.     Illustrated  by  30  double-plate  engravings. 

Contents. — Report  on  Filtration — London  "Works,  G-eneral — Chelsea 
"Water  Works  and  Pilters — Lambeth  Water  Y/orks  and  Filters — Southwark 
and  Vanxkall  Water  Works  and  Filters — Grand  Junction  Water  Works  and 
Filters — West  Middlesex  Water  Works  and  Filters — Kew  Eiver  Water 
Works  and  Filters — East  London  Water  Works  and  Filters — Leicester  Water 
Works  and  Filters — York  Water  Works  and  Filters — Liverpool  Water  Works 
and  Filters — Edinburgh.  Water  Yforks  and  Filters — Dublin  Yfater  Works 
and  Filters — Perth  Water  Works  and  Filtering-  Gallery — Berlin  Water 
Works  and  Filters — Hamburg-  Yf  ater  Works  and  Reservoirs — Altona  Water 
Works  and  Filters — Tours  Water  Works  and  Filtering-  Canal — Angers  Water 
Works  and  Filtering  Galleries — Nantes  Water  Works  and  Filters — Lyons 
Water  YvT'orks  and  Filtering  Galle]pies — Toulouse  Water  Works  and  Filtering 
Galleries — Marseilles  Water  Y/orks  and  Filters — Genoa  Water  W^orks  and 
Filtering  Galleries — Leghorn  Y/ater  Yf  orks  and  Cisterns — Wakefield  Yv^ater 
Works  and  Filters — Appendix. 


Tnnner  on  Roll-Tnrning. 

1  vol.  8vo.  and  1  vol.  plates.     ^10.00. 

A  TEEATISE  ON  EOLL-TUENINO  FOE  THE  MANUFAC^ 
TUEE  OF  lEON.  By  Peter  Ttjnneh.  Translated  and  adapted. 
By  John  B.  Peasse,  of  the  Pennsylvania  Steel  YYorks.  YYith. 
numerous  wood-cuts,  8vo.,  together  with  a  folio  atlas  of  10  Htho- 
graphed  plates  of  Eolls,  Measurements,  &c. 

"  We  commend  this  book  as  a  clear,  elaborate,  and  practical  treatise  upon 
the  department  of  iron  manufacturing  operations  to  which  it  is  devoted. 
The  -writer  states  in  his  preface,  that  for  twenty -five  years  -he  has  felt  the 
necessiiy  of  such  a  work,  and  has  evidently  brought  to  its  preparation  the 
fruits  of  experience,  a  painstaking  regard  for  accuracy  of  statement,  and  a 
desire  to  furnish  information  in  a  style  readily  understood.  The  book  should 
be  in  the  hands  of  every  one  interested,  either  in  the  general  practice  of 
mechanical  engineering,  or  the  special  branch  of  manufacturing  operations  to 
which  the  work  relates.'' — American  Artisan. 


10  SCIEN-TIFIG  BOOKS  FJIBLISHED  BT 

Jacob  on  Storage  Reservoirs. 

18mo.    Boards     50  cts. 

THE  DESIGNma  A^D  CONSTEUOTIOK  OF  STOEAGE 
EESERVOIRS.  By  Aethur  Jacob,  B.  A.  "With  tables  and 
wood-cuts  representing  sections,  etc. 


Heivsoii  on  Embankments. 

8sro.     Cloth.     $2.00. 

PEIlSrOIPLES  AND  PEACTICE  OP  EMBANKINa  LANDS 
from  Eiver  Ploods,  as  applied  to  tlie  Levees  of  tlie  Mississippi. 
By  William  HE\Yso]sr,  Civil  Engineer. 

"  This  is  a  valuable  treatise  on  the  principles  and  practice  of  embanking 
lands  from  river  floods,  as  applied  to  the  Levees  of  the  Mississippi,  by  a  highly 
intelligent  and  experienced  engineer.  The  author  says  it  is  a  first  attempt 
to  reduce  to  order  and  to  rule  the  design,  execution,  and  measurement  of  the 
Levees  of  the  Mississippi.  It  is  a  most  useful  and  needed  contribution  to 
scientific  literature. — PldladelpMa  Evening  Journal. 


Griiner  on  Steel. 

8vo.  Cloth.     $3.50. 

THE  MANUFACTUEE  OF  STEEL.  By  M.  L.  Geuttee,  trans- 
lated from  tlie  French.  By  Lenox  Smith,  A.  M.,  E.  M.,  vvrith  an 
appendix  on  the  Bessemer  Process  in  the  United  States,  by  the 
translator.     Illustrated  by  lithographed  drawings  and  wood-cuts. 

"  The  purpose  of  the  work  is  to  present  a  careful,  elaborate,  and  at  the 
same  time  practical  exaifiination  into  the  physical  properties  of  steel,  as  -well 
as  a  description  of  the  new  processes  and  mechanical  appliances  for  its  manufac- 
ture. The  information  which  it  contains,  gathered  from  many  trustworthy 
sources,  will  be  found  of  much  value  to  the  American  steel  manufacturer, 
who  may  thus  acquaint  himself  with  the  results  of  careful  and  elaborate  ex- 
periments in  other  countries,  and  better  prepare  himself  for  successful  com- 
petition in  this  important  industry  with  foreign  makers.  The  fact  that  this 
volume  is  from  the  pen  of  one  of  the  ablest  metallurgists  of  the  present  day, 
oannot  fail,  we  think,  to  secure  for  it  a  favorable  consideration. — Iron  Age, 


D.    VAN-  AWSTHAJVD.  11 

Banerman  on  Iron,  . 

12mo.  Cloth.     $2.0a 

TEEATISE  ON  THE  liETALLUEGT  OF  lEON.  Contain- 
ing outlines  of  the  History  of  Iron  Manufacture,  methods  of 
Assay,  and  analysis  of  Iron  Ores,  processes  of  manufacture  of 
Iron  and  Steel,  etc.,  etc.  By  H.  Baueemaist.  First  American 
edition.  Eevised  and  enlarged,  with  an  appendix  on  the  Martin 
Process  for  making  Steel,  from  the  report  of  Abram  S.  Hewitt. 
Illustrated  with  numerous  wood  engravings. 

"  TMs  is  an  important  addition  to  the  stock  of  technical  works  published  in 
this  country.  It  embodies  the  latest  facts,  discoveries,  and  j>rocesse8  con- 
nected with  the  manufacture  of  iron  and  steel,  and  should  be  in  the  hands  of 
every  person  interested  in  the  subject,  as  well  as  in  all  technical  and  scientific 
libraries." — ScientifiG  American. 


Link  and  Valve  Motions,  by  W,  S. 
AiicMncloss. 

Sixth  Edition.     8vo.  Cloth.     $3.00. 

APPLICATION  OF  THE  SLIDE  YALYE  and  Link  Motion  to 
Stationary,  Portable,  Locomotive  and  Marine  Engines,  with  new 
and  simple  methods  for  proportioning  the  parts.  By  Willia:i 
S.  AucHiNCLoss,  Civil  and  Mechanical  Engineer.  Designed  as 
a  hand-book  for  Mechanical  Engineers,  Master  Mechanics, 
Draughtsmen  and  Students  of  Steam  Engineering.  All  dimen- 
sions of  the  valve  are  found  with  the  greatest  ease  by  means  of 
a  Printed  Scale,  and  proportions  of  the  hnk  determined  vnthout 
the  assistance  of  a  model.  Illustrated  by  37  wood-cuts  and  2 1 
lithographic  plates,  together  with  a  copperplate  engraving  of  tlio 
Travel  Scale. 

All  the  matters  we  have  mentioned  are  treated  with  a  clearness  and  absence 
of  unnecessary  verbiage  which  renders  the  work  a  peculiarly  valuable  one. 
The  Travel  Scale  only  requires  to  be  known  to  be  apprecia-ted.  Mr.  A.  writes 
so  ably  on  his  subject,  we  wish  he  had  written  more.  London  Mri' 
gineering. 

We  have  never  opened  a  work  relating  to  steam  which  seemed  to  us  better 
calculated  to  give  an  intelligent  mind  a  clear  understanding  of  the  depart' 
ment  it  discusses. — ScientifiG  American. 


12  SCIENTIFIC  BOOKS  PUBLISHED  BY 

Slide  Yalve  by  EccentriGs^  by  Prof. 
C.  W.  MacCord, 

4to.    Illustrated.    Cloth,    f4.00. 

A  PEACTICAL  TEEATISE  ON  THE  SLIDE  YALYE  BY 
ECCENTEICS,  examining  by  metliods,  tlie  action  of  the  Eccen- 
tric upon  the  Slide  Yalve,  and  explaining  the  practical  proces- 
ses of  laying  out  the  movements,  adapting  the  valve  for  its 
various  duties  in  the  steam-engine.  For  the  use  of  Engineers, 
Draughtsmen,  Machinists,  and  Students  of  valve  motions  in 
general.  By  C.  "W.  MacCoed,  A.  M.,  Professor  of  Mechanical 
Drawing,   Stevens'  Institute  of  Technology,  Hoboken,  N  J. 


Stillman^s  Steam-Engine  Indicator 


12mo.  Cloth.     11.00. 


THE  STEAM-ENGINE  IN'DICATOE,  and  the  Improved  Mano- 
meter Steam  and  Yacuum  Gauges ;  their  utility  and  application 
By  Paul  Stillmak.     New  edition. 


Bacon's  Steam-Engine  Indioatoro 

12mo.  Cloth.     $1.00.     Mor.     $1.50. 

A  TEEATISE  ON  THE  EICHAEDS  STEAM-ENGINE  IN- 
DICATOE,  with  directions  for  its  use.  By  Ohaeles  T.  Poutee. 
■  Eevised,  with  notes  and  large  additions  as  developed  by  Amer- 
ican Practice,  with  an  Appendix'  containing  useful  formulae  and 
rules  for  Engineers.  By  P.  W.  Bacon,  M.  E.,  Member  of  the 
American  Society  of  Civil  Engineers.     Illustrated.    Second  Edition 

In  this  work,  Mr.  Porter's  book'  has  been  taken  as  the  basis,  but  Mr.  Bacon 
has  adapted  it  to  American  Practice,  and  has  conferred  a  great  boon  on 
American  Engineers. — Artisan. 


Steam  Boiler  Explosions. 

18mo.    Boards.    50  cts. 
STEAM  BOILEE  EXPLOSIONS.     By  Zeeah  OoLBUEif. 

"It  is  full  of  practical  information,  and  serves  to  show  in  a  most  marked 
manner  how  very  little  one's  knowledge  upon  the  subject  has  advanced  during 
the  past  ten  y ears. "— iV.  F.  Times.  '  . 


J).   VAJSr  J'WSTBAJSrJ).  13 

Gillmore's  Limes  and  Cements. 

Fifth  Edition,    Mevise.l  and  Enla7*gd. 

8vo.     Cloth.     $4.00. 

PEACTICAL  TEEATISE  ON  LIMES,  HTDEAULIO  CE- 
MENTS, AND  MOETAES.  Papers  oil  Practical  Engineering, 
U.  S.  Engineer  Department,  No.  9,  containing  Eeports  of 
numerous  experiments  conducted  in  New  York  City,  during  the 

years  1858  to   1861,  inclusive.     By  Q.  A.  G-illmoke,  Lt.-Ool. 

TJ.  S.  Corps  of  Engineers,  Brevet  Major-G-eneral  U.  S.  x\rmy. 

With  numerous  illustrations. 

"  TMs  work  contains  a  record  of  certain  experiments  and  researclies  made 
under  the  authority  of  the  Engineer  Bureau  of  the  "War  Department  from 
1858  to  1861,  upon  the  various  hydraulic  cements  of  the  United  States,  and 
the  materials  for  their  manufacture.  Tlie  experiments  were  carefully  made, 
and  are  well  reported  and  compiled. ' — Journal  Franklin  Institute. 


Qillmore^s  Ooignet  Beton, 


COIGNET  BETON  AND  OTHEE  AETIFICIAL  STONE.  By 
Q.  A.  G-iLLMORE,  Lt.-Col.  U.  S  Corps  of  Engineei-s,  Brevet 
Major-General  U.  S.  Army.     9  Plates,  Views,  etc. 

This  work  describes  with  considerable  minuteness  of  detail  the  several  kinds 
of  artificial  stone  in  most  general  use  in  Europe  and  now  beginning  to  be 
introduced  in  the  United  States,  discusses  their  properties,  relative  merits, 

and  cost,  and  describes  the  materials  of  which  they  are  composed 

The  subject  is  one  of  special  and  growing  interest,  and  we  commend  the  work, 
embodying  as  it  does  the  matured  opinions  of  an  experienced  engineer  and 
expert. 


Gillmore  on  Roads. 

ISmo.  Cloth.     In  Press. 

A  PEACTICAL  TEEATISE  ON  THE  CONSTEUCTION 
OF  EOADS,  STEEETS,  AND  PAVEMENTS.  By  Q.  A. 
GiLLMORE,  Lt.-Col.  U.  S.  Corps  of  Engineers,  Brevet  Major- 


14       ■    SCIEI^TTIFIC  BOOKS  PUBLISHED  BY 


Willianisoii  on  tlie  Barometer, 

4to.  Clotk  $15.00. 
ON  THE  USE  OF  THE  BAEOMETEE,  ON  SURYEYS  AND 
EECONNAISSANGES.-  Part  I.  Meteorology  ia  its  Connec- 
tion with  Hypsometry.  Part  II.  Barometric  Hypsometry.  By 
E.  S.  WiLLiAiisox,  Bvt.  Lieiit.-Col.  IT.  S.  A.,  Major  Corps  of 
Engineers.  Witli  Illustrative  Tables  and  Engravings.  Paper 
No.  15,  Professional  Papers,  Corps  of  Engineers. 

"  Sak  Francisco,  Gal.,  Fe'o.  27,  1867. ' 
*'  G-en.  A.  A.  Humphreys,  Cliief  of  Engineers,  U.  S.  Army  : 

"  G-SNERAL, — I  liave  the  honor  to  submit  to  you,  in  the  following  pages,  the 
results  of  my  investigations  in  meteorology  and  hypsometry,  made  with  the 
view  of  ascertaining  how  far  the  barometer  can  be  used  as  a  reliable  instru- 
ment for  determining  altitudes  on  extended  lines  of  survey  and  reconnais- 
sances. These  investigations  have  occupied  the  leisure  permitted  me  from  my 
professional  duties  during  the  last  ten  years,  and  I  hope  the  results  will  be 
deemed  of  suSicient  value  to  have  a  place  assigned  them  among  the  printed 
professional  papers  of  the  United  States  Corps  of  Engineers. 
"  Very  respectfully,  your  obedient  servant, 

'•'R.  S.  WILLIAMSON, 
"  Bvt.  Lt.-Col.  U.  S.  A.,  Major  Corps  of  U.  S.  Engineers." 


Yon  Cottars  Ore  Deposits, 

Svo.     Cloth.     $4.00. 
TEEATISE  ON  OEE  DEPOSITS.      By  Berkhaed  Yok  Cotta, 
Professor  of  Geology  in  tlie  Eoyal  ScKooI  of  Mines,  Ereidberg, 
Saxony.      Translated    from    the     second    German    edition,    by 
Prederick    Prime,    Jr.,    Mining  Engineer,   and  revised  by  tbo 
author,  witk  numerous  illustrations. 
"  Prof.  Yon  Cotta  of  the  Erciberg   School  of  Mines,  is  the  author  of  the 
best  modern  treatise  on  ore  deposits,   and  wo  are  heartily  glad  that  this  ad- 
m.irable  work  has  been  translated  and  x^tiblishcd  in  this  country.     The  trans- 
lator, Mr.  Frederick  Prime,  Jr.,  a  graduate  of  Preiberg,  has  had  in  his  Avork 
the  great  advantage  of  a  revision  by  the  author  himself,  who  declares  in  a 
prefatory  note  that  this  may  bo  considered  as  a  new  edition  (the  third)  of  his 
own  book. 

"  It  is  a  timely  and  welcome  contribution  to  the  literature  of  mining  in 
this  country,  and  we  are  grateful  to  the  translator  for  his  enterprise  and  good 
judgment  in  undertaking  its  preparation  ;  while  we  recognize  with  equal  cor- 
diality the  liberality  of  th«  author  in  granting  both  permission  and  assist- 
ance."— Extract  from  Bemeio  in  Engineering  and  Mining  Jourrud. 


D.  VAK  ITOQTRAl^J).  15 

Plattner's  Blow-Pipe  Analysis, 

Second  edition,    Eevised.     8vo.     Clotli.     $7.50. 

PLATT-NEE'S  MANUAL  OF  QUALITATIVE  AND  QUAN- 
TITATIYE  ANALYSIS  Y/ITH  THE  BLOYv^-PIPE.  Prom 
tlie  last  German  editioa  Pevised  and  enlarged.  By  Prof.  Tn. 
PiCHTEE,  of  the  Poyal  Saxon  Mining  Academy.  Translated  by 
Prof.  H.  B.  CoPcNWALL,  Assistant  in  tlie  Columbia  School  of 
Mines,  New  York ;  assisted  by  Joii:^^  H.  Caswell.  Illustrated 
with,  eighty-seven  wood-cuts  and  one  Lithographic  Plate.  5G0 
pages. 

"  Plattner's  celebrated  "work  lias  long  been  recognized  as  tbo  only  complete 
book  on  Blo-^7-Pipe  Analysis.  Tho  fourth.  German  edition,  edited  by  Prof. 
Bicbter,  fully  sustains  tbe  rejputation  wbicb  the  earlier  editions  accj^uired  dur- 
ing tbe  lifetime  of  tlie  author,  and  it  is  a  source  of  great  satisfaction  to  us  to 
know  that  Prof.  Pichter  has  co-operated  -witli  tho  translator  in  issuing  the 
American  edition  of  the  work,  -which  is  in  fact  a  iiftb  edition  of  the  original 
■work,  being  far  more  complete  than  the  last  German  edition." — SiUiman^s 
Journal. 

There  is  nothing  bo  complete  to  be  found  in  the  English  language.  Platt- 
ner's book  is  not  a  m.ere  pocket  edition  ;  it  is  ia tended  as  a  comprehensive  guide 
to  all  that  is  at  present  kno^vn  on  the  blow-pipe,  and  as  such  ia  really  indis- 
pensable to  teachers  and  advanced  pupils. 

"  Mr.  Cornwall's  edition  is  something  more  than  a  translation,  as  it  contains 
many  corrections,  emendations  and  additions  not  to  be  found  in  the  original. 
It  is  a  decided  improvement  on  the  work  in  its  German  dress." — Journal  of 
Applied  Chemistry, 


Egleston's  Mineralogy, 

8to.     Illustrated  with  84  Lithographic  Plates.     Cloth.     $4.50. 

LECTUEES  ON  DESCEIPTIYE  MINERALOGY,  Delivered 
at  the  School  of  Mines,  Columbia  College.  Br  Pegeessob  T. 
Egleston". 

These  lectures  are  what  their  title  indicates,  the  lectures  on  Mineralogy 
delivered  at  the  School  of  Mines  of  Columbia  College.  They  have  beea 
printed  for  the  students,  in  order  that  more  time  might  bo  given  to  the  vari- 
ous methods  of  examining  and  determining  minerals.  The  second  part  has 
only  been  printed.  The  first  part,  comprising  crystallography  and  physical 
mineralogy,  will  be  printed  at  some  future  time. 


IG  8CIE2-TTIFIC  PAjOIIS  FUBLI3HEI)  BY 

Pynchon's  Chemical  Physics, 

New  Edition.    Mevlsed  and  Enlarged, 
Crown  8vo.     Clotli.     $3.00. 

INTEODUCTION  TO  CHEMICAL  PHYSICS,  Designed  for  the 
Use  of  Academies,  Colleges,  and  Higli  Schools,  Illustrated  with 
numerous  engravings,  and  containing  copious  experiments  witli 
directions  for  preparing  tliem.  By  T]io]sias  Kuggles  Pyxcho:^-, 
M.A.,  Professor  of  Chemistry  and  the  Natural  Sciences,  Trinity 
College,  Hartford. 

Hitherto,  no  work  suitable  for  general  use,  treating  of  all  these  subjects 
"within  tho  limits  of  a  single  Toluiac,  could  bo  found  ;  consequently  tho  atten- 
tion they  have  receiTod  has  not  been  at  all  proportionate  to  their  intportanco. 
It  is  believed  that  a  book  containing  so  much  valuable  information  within  so 
small  a  compass,  cannot  fail  to  meet  with  a  ready  sale  among  all  intelligent 
.  persons,  while  Professional  men.  Physicians,  Medical  Students,  Photogra.ph- 
ers,  Telegraphers,  Engineers,  and  Artisans  generally,  will  find  it  specially 
valuable,  if  not  nearly  indispensable,  as  a  book  of  reference. 

"  We  strongly  recommend  this  able  treatise  to  GUI',  readers  as  the  first 
work  ever  published  on  the  subject  free  from  perplexing  technicalities.  In 
style  it  is  pure,  in  description  graphic,  and  its  typographical  appearance  is 
artistic.     It  is  altogether  a  most  excellent  work." — EdcctiG  Medical  Journal. 

"  It  treats  fully  of  Photography,  Telegraphy,  Steam  Engines,  and  the 
various  applications  of  Electricity.  In  short,  it  is  a  carefully  prepared 
volume,  abreast  with  the  latest  scientific  discoveries  and  inventions.'' — Hart- 
ford Courant. 

Plympton's  Blow-Pipe  Analysis, 

12mo.     Cloth.     $1 50. 

THE  BLOW-PIPE  :  A  Guide  to  Its  Use  in  the  Determination 
of  Salts  and  Minerals.  Compiled  from  yarious  sources,  by 
G-EOEGE  W.  Plymp1:ois^,  C.E.,  A.M.,  Professor  of  Physical 
Science  in  tlie  Polytechnic  Institute,  Brookl}^,  ¥.  Y. 

"  This  manual  probably  has  no  superior  in  the  English  language  as  a  text- 
book for  beginners,  or  as  a  guide  to  the  student  working  without  a  teacher. 
To  the  latter  many  illustrations  of  the  utensils  and  apparatus  required  in 
using  the  blow-pipe,  as  well  as  the  fully  illustrated  description  of  the  blow- 
pipe fiame,  will  bo  especially  serviceable."— iVfiio  York  Teacher, 


D.    VAN-  N08TRAND, 


Ure^s  Dictionary, 

Sixth   Edition, 

London,  1872. 
3  vols.     Half  Eussia,  $32.50. 

DICTIONAEY  OF  ABTS,  MANUFACTUEES,  AND  MINES. 
By  A]s"D3iEW  Uee,  M.D.  Sixth,  edition.  Edited  by  Egbert  Hunt, 
E.E.S.,  greatly  enlarged  and  rewritten. 


Gases  in  Coal  Mines. 

18mo.     Boards.     50  cts. 

A  PEACTIOAL  TEEATISE  ON  THE  GASES  MET  WITH 
IN  COxiL  MINES.  By  the  late  J.  J.  Atkiksoi.-,  Govem- 
ment  Inspector  of  Mines  for  the  County  of  Durham,  England. 


Watt's  Dictionary  of  Chemistry. 

Supplementary  Volume* 

8vo.    Cloth.     $9.00. 

This  volnme  brings  the  E,ecord  of  Chemical  Discovery  down  to  the  end  of 
the  year  1889,  including'  also  several  additions  t-o,  and  corrections  of,  former 
results  -which  have  appeared  in  1870  and  1871. 

*"^^""  Complete  Sets  of  the  Work,  New  and  Revised  edition,  including  above 
supx^lement.     G  vols.     8vo.     Cloth.     $62.00. 


Rammelsljerg's  Chemical  Analysis. 

Svo.     Cloth.     $2.25. 

GUIDE    TO    A    COUBSE  OF  QUANTITATIYE   CHEMICAL 

ANALYSIS,  ESPECIALLY  OF  MINEEALS  AND  FUE- 
NACB  PEODUCTS.  Illustrated  by  Examples.  By  C.  F. 
EAUiiELSBERG.     Translated  by  J.  Towlee,  M.D. 

This  work  has  been  translated,  and  is  now  published  expressly  for  those 
students  in  chemistry  whose  time  and-  other  studies  in  colleges  do  not  permit 
them  to  enter  upon  the  more  elaborate  and  expensive  treatises  of  Preseniua 
and  others.  It  is  the  condensed  labor  of  a  master  in  chemistry  and  of  a  prac- 
tical analyst. 


18  BGISJ^TIFIO  BOOKS  PUBLISHED  BY 

Eliot  and  Storer's_  Qualitative 
Clieniical  Analysis, 

NeiA)  Edition,  Mevised. 
12mo.     inustrated.     Clotli.     81.50. 

A   COMPENDIOUS  MANUAL  OF  QUALITATIVE  OHEMI^ 

CAL  ANALYSIS.  By  Chables  W.  Eliot  and  FhaitkH.  StopvEh. 
Hevised  with,  tlio  Coopei-ation  of  tlie  Aiitliors,  by  "William  Hip- 
lEY  Nichols,  Professor  of  Chemistry  in  the  Massachusetts  Insti- 
tute of  Technology. 

"  TMs  Manual  has  great  merits  as  a  practical  introductioii  to  tiie  science 
and  the  art  of  which  it  treats.  It  contains  enough  of  the  theory  and  practice 
of  qualitative  analysis,  "  in  the  wet  way,"  to  bring  out  all  the  reasoning  in- 
volved in  the  science,  and  to  present  clearly  to  the  student  the  most  approved 
methods  of  the  art.  It  is  specially  adapted  for  exercises  and  experiments  in 
the  labora-tory;  and  yet  its  classifications  and  manner  of  treatment  are  so 
systematic  and  logical  throughout,  as  to  adapt  it  in  a  high  degree  to  that 
higher  class  of  students  generally  who  desire  an  accurate  knowledge  of  the 
practical  methods  of  arriving  at  scientific  facts." — Lutheran  Observer. 

"  "We  wish  every  academical  class  in  the  land  could  have  the  benefit  of  the 
fifty  exercises  of  two  hours  each  necessary  to  master  this  book.  Chemistry 
would  cease  to  be  a  mere  matter  of  mem.ory,  and  become  a  pleasant  experi- 
mental and  intellectual  recreation.  "We  heartily  commend  this  little  volume 
to  the  notice  of  those  teachers  who  believe  in  using  the  sciences  as  means  of 
mental  discipline." — College  Courant. 


Craig's  Decimal  System,     - 

Square    32mo.     Limp.     50c. 

WEIGHTS  AND  MEASURES.  An  Account  of  the  Decimal 
System,  with  Tables  of  Conversion  for  Commercial  and  Scientific 
Uses.     By  B.  E.  Ceaig,  M.  D. 

"  The  most  lucid,  accurate,  and  useful  of  all  the  hand-books  on  this  subject 
that  we  have  yet  seen.  It  gives  forty-seven  tables  of  comparison  between  the 
English  and  Trench  denominations  ex  length,  area,  capacity,  weight,  and  the 
CentigTade  and  Fahrenheit  thermometers,'  with  clear  instructions  how  to  use 
them ;  and  to  this  practical  portion,  which  helps  to  make  the  transition  as 
easy  as  possible,  is  prefixed  a  scientific  explanation  of  the  errors  in  the  metrio 
By  stem,  and  hov/  they  may  be  corrected  in  the  laboratory." — Nation. 


B.   VAN  JSrOSTBAJSri).  19 


Nugent  on  Optics. 

12nio.      Clotli.     $2.00 

TEEATISE  ON  OPTICS ;  or,  Light  and  Sight,  theoretically  and 

practically  treated  ;  -with  the  application  to  Fine  Art  and  Indus- 
trial Pursuits.  By  E.  Nugent.  With  one  hundred  and  three 
illustrations. 

"  This  book  is  of  a  practical  rather  than  a  theoretical  kind,  and  is  de- 
signed to  afford,  accurate  and  complete  information  to  all  interested  in  appli- 
cations of  the  science." — Round  Table. 


Barnard's  Metric  System, 

8vo.     Brown  cloth.     $3.00. 

THE   METPIO  SYSTEM  OF  WEIGHTS   AND  MEASUEES. 

An  Address  delivered  before  the  Convocation  of  the  University  of 
the  State  of  New  York,  at  Albany,  August,  1871.  By  Eredemck: 
A.  P.  Bar]?^ AED,  President  of  Columbia  College,  New  York  City. 
Second  edition  from  the  Pevised  edition  printed  for  the  Trustees 
of  Columbia  College.     Tinted  paper. 

"It  is  the  best  summary  of  the  arguments  in.  favor  of  the  metric  weights 
and  measures  with  which  we  are  acquainted,  not  only  "because  it  contains  in 
sniall  space  the  leading  facts  of  the  case,  but  because  it  puts  the  advocacy  of 
that  system  on  the  only  tenable  grounds,  namely,  the  great  convenience  of  a 
decimal  notation  of  weight  and  measure  as  well  as  money,  the  value  of  inter- 
national uniformity  in  the  matter,  and  tho  fact  that  this  metric  system  is 
adopted  ani  in  general  use  by  the  majority  of  civilized  nations." — The  Natlort- 


Butler  on  Yentilation, 

18mo.    Boards.    50  cts. 

VENTILATION    OF    BUILDINGS.      By    W.    F.     Butler. 

Illustrated. 

'■'•  As  death  by  insensible  siLSocation  is  cue  of  the  prominent  causes  which 
swell  ooi-  bills  of  mortality,  we  commend  this  book  to  the  attention  of  philan- 
thropists as  weU  as  to  architects."— Uosioii  Globe. 


20  SCIERTIFIC  BOOKS  PUBLISHED  BY 

Harrison's  MechaiiiG's  Tool-Book, 

12mo.     Cloth.     $1.50. 

MECHANIC'S  TOOL  BOOK,  with  practical  rules  and  suggestions, 
for  tlie  use  of  Machinists,  Iron  Workers,  and  others.  By  W.  B. 
HAERisoiT,  Associate  Editor  of  the  "  American  Artisan."  Illustra- 
ted with  4U-  engravings. 

"  This  work  is  specially  adapted  to  meet  the  wants  of  Machinists  and  work- 
ers in  iron  generally.  It  is  made  np  of  the  work-day  experience  of  an  intelli- 
gent and  ingenious  mechanic,  who  had  the  faculty  of  adapting  tools  to  various 
purposes.  The  practicability  of  his  plans  and  suggestions  are  made  apparent 
even  to  the  unpractised  eye  hy  a  series  of  well-executed  wood  engravings." — 
PMladelplda  Inquirer. 


Pope's  Modern  Practioe  of  the  Elec- 
tric Telegraph, 

Ninth   Sdition.    8vo.    Cloth     $2.00. 

A  Hand-book  for  Electricians  and  Operators.      By  Fii^nk  L.  Pope. 
Seventh  edition.     E-evised  and  enlarged,  and  fully  illustrated. 

Extract  from  Letter  of  Prof.  Morse. 

"  I  have  had  time  only  cursorily  to  examine  its  contents,  but  this  examina- 
tion has  resulted  in  great  gratification,  especially  at  the  fairness  and  unpre- 
judiced tone  of  your  whole  work. 

"  Your  illustrated  diagrams  are  admirable  and  beautifully  executed. 

"  I  think  all  your  instructions  in  the  use  of  the  telegraph  apparatus  judi- 
cious and  correct,  and  I  most  cordially  wish  you  success." 

Extract  from  Letter  of  Prof.  G.  W.  Hough,  of  the  Dudley  Observatory. 

"  There  is  no  other  work  of  this  kind  in  the  English  language  that  con- 
tains in  so  small  a  corapass  so  much  practical  information  in  the  application 
of  galvanic  electricity'  to  telegraphy.  It  should  be  in  the  hands  of  every  one 
interested  in  telegraphy,  or  the  use  of  Batteries  for  other  purposes." 


Morsels  Telegraphic  Apparatus. 

Illustrated.     8vo.     Cloth.     $2.00. 

EXAMINATION  OF  THE  TELEGEAPHIC  APPARATUS 
AND  THE  PPOCESSES  IN  TELEGAPHY.  By  Samuel  E. 
B.  Mouse,  LL.D.,  United  >States  Commissioner  Paris  Universal 
Exposition,  1867. 


D.  VAI^  NO  STRAND.  21 

m- — - 

Sabine's  History  of  the  Telegraph. 

12mo.  Cloth.     $1.25. 

HISTOBY  AND  PHOGEESS  OF  THE  ELECTRIC  TELE- 
GRAPH, with.  Descriptions  of  some  of  tlie  Apparatus.  By 
Egbert  Sa.bi]n^e,  C.  E.     Second  edition,  with,  additions. 

Contents. — I.  Early  Observations  of  Electrical  Phenomena.  II.  Tele- 
graphs by  Frictional  Electricity.  III.  Telegraphs  by  "Voltaic  Electricity. 
IV.  Telegraphs  by  Electro-Magnetism  and  Magneto-Electricity.  V.  Tele- 
graphs now  in  use.  VI.  Overhead  Lines.  VII.  Submarine  Telegraph  Lines- 
VIII.  Underground  Telegraphs.     IX.  Atmospheric  Electricity. 


Haskins^    Galvanometer. 

Pocket  form.     Illustrated.     Morocco  tucks.     $2.00. 

THE  GALVANOMETER,  AIN^D  ITS  USES ;    a  Manual  for 
Electricians  and  Students.     By  0.  H.  Haskus-s. 

"  We  hope  this  excellent  little  work  will  meet  with  the  sale  its  merits 
entitle  it  to.  To  every  telegrapher  who  ownS;  or  uses  a  Galvanometer,  or 
ever  expects  to,  it  will  be  quite  indispensable." — The  Telegrapher. 


Cnlley's  Hand-Book  of  Telegraphy. 

8vo.     Cloth.    $5.00. 
A  HAND-BOOK   OF  PRACTICAL  TELEGKAPHY.      By 

E.  S.  CuLLEY,  Engineer  to   the  Electric  and  International 
Telegraph.   Company.     Fifth  edition,  revised  and  enlarged. . 


Foster's  Submarine  Blasting. 

4to.     Cloth.     13.50. 

SUBMABINE  BLASTING  in  Boston  Harbor,  Massachusetts- 
Removal  of  Tower  and  Corwin  Bocks.  By  Jonas'  G.  Foster, 
Lieutenant-Colonel  of  Engineers,  and  Brevet;  Major- General,  U. 
S.  Army.     Illustrated  with  seven  plates. 

List  of  Plates. — 1.  Sketch  of  the  -Narrows,  Boston  Harbor.  3. 
Townsend's  Submarine  Drilling  Machine,  and  "Working  Vessel  attending. 
3.  Submarine-  Drilling  Machine  employed.  4.  Details  of  Drilling  Macliine 
employed.  5.  Cartridges  and  Tamping  used.  G,  Euses  and  Listilat.ed  Wireg 
used.     7.  Portable  Friction  Battery  used. 


22  8GIENTIFIG  BOOKS  PUBLISHED  BY 

Barnes'  Submarine  Warfare. 

8vo.     Cloth.     $5.00. 

SUBMAEINE  WAEFAEE,  DEFENSIVE  AND  OFFENSIVE. 
Comprising  a  full  and  complete  History  of  the  Invention  of  the 
Torpedo,  its  employment  in  War  and  results  of  its  use.  De- 
scriptions of  the  yarious  forms  of  Torpedoes,  Submarine  Batteries 
and  Torpedo  Boats  actually  used  in  War.  Methods  of  Ignition 
by  Machinery,  Contact  Fuzes,  and  Electricity,  and  a  full  account 
of  experiments  made  to  determine  the  Explosive  Force  of  Grun- 
powder  under  Water.  Also  a  discussion  of  the  Offensive  Torpedo 
system,  its  effect  upon  Iron-Clad  Ship  systems,  and  inffuenco  upon 
Future  Naval  Wars.  By  Lieut. -Commander  Jonii  S.  Baexes, 
U.  S.  N.     Y/ith  twenty  lithographic  plates  and  many  wood-cuts. 

*'  A  book  important  to  military  men,  and  especially  so  to  engineers  and  ar- 
tillerists. It  consists  of  an  examination  of  the  varions  offensive  and  defensive 
eng-ines  that  have  been  contrived  for  submarine  hostilities,  including  a  discus- 
sion of  the  torpedo  system,  its  effects  upon  iron-clad  ship-systems,  and  its 
probable  influence  upon  future  naval  wars.  Plates  of  a  valuable  character 
accompany  the  treatise,  which  affords  a  useful  history  of  the  momentous  sub- 
ject it  discusses.  A  great  deal  of  useful  information  is  collected  in  its  pages, 
especially  concerning  the  inventions  of  SCHOLL  and  Vekdu,  and  of  JoNEs' 
and  Hunt's  batteries,  as  well  as  of  other  similar  machines,  and  the  use  in 
submarine  operations  of  gun-cotton  and  nitro-glycerine." — N.  Y.  Times, 


Randairs  Quartz  Operator's  Hand- 

Book. 

12mo.     Cloth.     ^3.00. 

QUARTZ  OPEEATOE'S    HAND-BOOK.     By   P,  M.  Randall, 
New  edition,  revised  and  enlarged.     Pully  illustrated. 

The  object  of  this  work  has  been  to  present  a  clear  and  comprehensive  ex- 
position of  mineral  veins,  and  the  means  and  modes  chiefly  employed  for  the 
mining  and  working  of  their  ores — more  especially  those  containing  gold  and 
silver. 


D.    VAST  JSrOSTJlAHD.  23 


McOullocii's  Theory  of  Heat. 

8vo.  Clotli.    In  Press. 

AN  ELEMEISTTAEY  TSEATISE  01^  THE  MEOHAJSTI- 
CAL  THEOEY  OF  HEAT,  AND  ITS  APPLICATION 
TO   AIR  AND   STEAM  ENGINES.     By  Prof.   R.   S.  Mc- 

CULLOCH. 


Benet^s  Chronoscope. 

Second  Edition, 

niustrated.     4to.     Cloth.     $3.00. 

ELEOTEO-BALLISTIC  MACHINES,  and  the  Schultz  Clirono- 
scope.  By  Lieutenant-Colonel  S.  Y.  Be]S"et,  Captain  of  Ordnance, 
U.  S.  Army. 

Contents. — 1.  Ballistic  Pendulum.  2.  Gun  Pendulum.  8.  Use  of  Elec- 
tricity. 4.  Navez' Machine.  5.  Yignotti's  Machine,  with  Plates.  G.Benton's 
Electro-Ballistic  Pendulum,  with  Plates.  7.  Leur's  Tro-Pendulum  Machine 
8.  Schultz's  Chronoscope,  with  two  Plates. 


Micliaelis'  Chronograph. 

4to.     Illustrated.     Cloth.     $3.00. 

THE  LE  BOULENGE  CHEONOGEAPH.  With  three  litho- 
graphed folding  plates  of  illusti^ations.  By  Brevet  Captain  0  E. 
MiCHAELis,  Eirst  Lieutenant  Ordnance  Corps,  IJ.  S.  Army. 

"  The  excellent  monograph  of  Captain  Michaelis  enters  minutely  into  the 
details  of  construction  and  management,  and  gives  tables  of  the  times  of  flight 
calculated  upon  a  given  fall  of  the  chronometer  for  all  distances.  Captain 
Michaelis  has  done  good  service  in  presenting  this  work  to  his  brother  officers, 
describing,  as  it  does,  an  instrument  which  bids  fair  to  be  in  constant  use  in 
©ur  future  ballistic  experiments.' — Army  and  Navy  Jourjuft 


24  BCIENTlFia  BOOKS  PUBLISHED  BY 

Silversmith's  Hand-Book, 

Fourth  Edition. 

Illustrated.     12mo.     Clotli.     $3.00. 

A  PKACTIOAL  HAND-BOOK  FOE  MINEBS,  Metallurgists, 
and  Assayers,  comprising  the  most  recent  improvements  in  tho 
disintegration,  amalgamation,  smelting,  and  parting  of  tho 
Precious  Ores,  with,  a  Comprehensive  Digest  of  the  Mining 
Laws.  Greatly  augmented,  revised,  and  corrected.  By  Julius 
Silversmith.  Fourth  edition.  Profusdy  illustrated.  1  vol. 
12mo.     Cloth.     $3.00. 

One  of  the  most  important  features  of  this  work  is  that  in  which  the 
metallurg-y  of  the  precious  metals  is  treated  of.  In  it  the  author  has  endeav- 
ored to  embody  all  the  processes  for  the  reduction  and  manipulation  of  tho 
precious  ores  heretofore  successfully  employed  in  G-ermany,  England,  Mexico, 
and  the  United  States,  together  with  such  as  have  been  more  recently  invented, 
and  not  yet  fully  tested — all  of  which  are  profusely  illustrated  and  easy  of 
comprehension. 


Simms'  Levelling, 

8vo.     Cloth.     $2.50. 

A  TEEATISE  ON  THE  PRINCIPLES  AND  PEACTICE  OF 
LEVELLING,  showing  its  application  to  purposes  of  Pailway 
Engineering  and  the  Construction  of  Poads,  &c.  By  Frederick 
"W.  SiMMS,  C.  E.  From  the  fifth  London  edition,  revised  and 
corrected,  with  the  addition  of  Mr.  Law's  Practical  Examples  for 
Setting  Out  Pailway  Curves.  Illustrated  with  three  lithogTaphic 
plates  and  numerous  wood-cuts. 

"  One  of  the  most  important  text-books  for  the  general  surveyor,  and  there 
is  scarcely  a  question  connected  with  levelling  for  which  a  solution  would  be 
sought,  but  that  would  be  satisfactorily  answered  by  consulting  this  volume." 
— Mining  Journal. 

"The  text-book  on  levelling  in  most  of  our  engineering  schools  and  col- 
leges."— Engineers. 

"The  publishers  have  rendered  a  substantial  service  to  the  profession, 
especially  to  the  younger  members,  by  bringing  out  the  present  edition  of 
Mr.  Simms'  useful  work." — Engineering, 


D,  VAN  XO&TRAND.  25 

Stuart's    Successful    Engineer. 

18mo.    Boards.    90  cents. 
HOW  TO  BECOME  A  SUCCESSFUL  EXGINEEE:  Being 
Hints  to  Youths  intending   to   adopt  the  Profession.      By 
Ber;n"Aed  Stuart,  Engineer.     Sixth  Edition. 

"  A  valuable  little  book  of  sound,  sensible  advice  to  young  men   wlio 
wisli  to  rise  in  tlie  most  important  of  the  professions." — Scientific  American. 


Stuart's  Naval  Dry  Docks, 

Twenty-four  engravings  on  steel. 
Fourth  Edition, 

4to.     Cloth.     SG.OO. 

THE  NAYAL  DRY  DOCKS  OF  THE  UNITED  STATES. 
By  Chaeles  B.  Stuaet.  Engineer  in  Chief  of  the  United  States 
Navy. 

Jjist  of  Illustratio7is. 

Pumping  Engine  and  Pumps — Plan  of  Dry  Dock  and  Pump-"\Yell  -  Sec- 
tions of  Dry  Dock — Engine  House — Iron  Floating  Gate — Details  of  Floating 
Gate — Iron  Turning  Gate — Plan  of  Tiirning  Gate — Culvert  Gate — Filling 
Culvert  Gates — Engine  Bed — Plate,  Pumps,  and  Culvert — Engine  House 
Eoof — Floating  Sectional  Dock — Details  of  Section,  and  Plan  of  Turn-Tables 
— Plan  of  Basin  and  Marine  Railways — Plan  of  Sliding  Frame,  and  Elevation 
of  Pumps — Hydraulic  Cylinder — Plan  of  Gearing  for  Pumps  and  End  Floats 
— Perspective  View  of  Dock,  Basin,  and  Railway — Plan  of  Basin  of  Ports- 
mouth. Dry  Dock — Floating  Balance  Dock — Elevation  of  Trusses  and  the  Ma- 
chinery— Perspective  View  of  Balance  Dry  Dock 


Free  Hand  Drawing. 

Profusely  Illustrated.     18mo.    Boards.     50  cents. 

A  GUIDE  TO  ORNAMENTAL,  Figure,   and  Landscai^e  Draw- 
ing.    By  an  Art  Student. 

Contents. — Materials  employed  in  Drawing,  and  how  to  use  them — On 
Lines  and  how  to  Draw  them — On  Shading — Concerning  lines  and  shading, 
with  applications  of  them  to  simple  elementary  subjects — Sketches  from  Na- 
ture. 


26  8CIENTIFIG  BOOKS  PUBLISHED  BY 

Minifie  s  Mechanical  Drawing. 

Ninth   Edition. 

Boyal  8vo,     Cloth.  ►  $4.00. 

A  TEXT-BOOK  OF  GEOMETEICAL  DEAWING  for  the  usp 
of  Mechanics  and  Schools,  in  which  the  Definitions  and  Rules  of 
Geometry  are  famiharly  explained ;  the  Practical  Problems  aro 
arranged,  from  the  most  simple  to  the  more  complex,  and  in  their 
description  technicalities  are  avoided  as  much  as  possible.  With 
illustrations  for  Drawing  Plans,'  Sections,  aijd  Elevations  of 
Buildings  and  Machinery ;  an  Introduction  to  Isometrical  Draw- 
ing, and  an  Essay  on  Linear  Perspective  and  Shadows,  Illus- 
trated with  over  200  diagrams  engraved  on  steel.  By  Wm, 
Minifie,  Architect.  Eighth  Edition.  With  an  Appendix  on  the 
Theory  and  Application  of  Colors. 

"  It  is  the  best  work  on  Drawing  that  we  have  ever  seen,  and  is  especially  a 
text-book  of  Geometrical  Drawing  for  the  use  of  Mechanics  and  Schools.  No 
young  Mechanic,  such  as  a  Machinist,  Engineer,  Oabinet-ilaker,  Millwright, 
or  Carpenter,  should  be  without  it." — Scientific  American. 

"  One  of  the  most  comprehensive  works  of  the  kind  e-^er  published,  and  can- 
not but  possess  great  value  to  builders.  The  style  is  at  omce  elegant  and  snh- 
st-:xatiaX.'^— Pennsylvania  Inquirer. 

"  "Whatever  is  said  is  rendered  perfectly  intelligible  by  remarkably  well- 
executed  diagrams  on  steel,  leaving  nothing  for  mere  vague  supposition ;  and 
the  addition  of  an  introduction  to  isometrical  drawing,  linear  perspective,  and 
the  projection  of  shadows,  winding  up  with  a  useful  index  to  technical  terms." 
— Glasgoio  Mechanics'  Journal. 

^^  The  British  Government  has  authorized  the  use  of  this  book  in  their 
schools  of  art  at  Somerset  House,  London,  and  throughout  the  kingdom. 


Minifle's  Geometrical  Drawing. 

New  Edition.    Enlarged. 

12mo.     Cloth.     $2.00. 

GEOMETEICAL  DEAWING.  Abridged  from  the  octavo  edition, 
for  the  use  of  Schools.  Illustrated  with  48  steel  plates.  New 
edition,  enlarged. 

*•  It  is  well  adapted  as  a  text-book  of  drawing  to  b^  used  in  our  High  Schools 
and  Academies  where  this  useful  branch  of  the  fine  arts  has  been  hitherto  too 
much  neglected." — Boston  Journal. 


D.   VAIf  NOSTUAND.  27 

Bell  on  Iron  Smelting. 

8vo.     Cloth.     $6.00. 

CHEMICAL  PHENOMENA  OF  lEON  SMELTING.  An  ex- 
perimental and  practical  examination  of  the  circumstances  which, 
determine  the  capacity  of  the  Blast  Eurnace,  the  Temperature 
of  the  Air,  and  the  Proper  Condition  of  the  Materials,  to  be 
operated  upon.     By  I.  LowTHiATi  Bell. 

"  The  reactions  which  take  place  in  every  foot  of  the  blast-furnace  have 
been  investigated,  and  the  nature  of  every  step  in  the  process,  from  the  intro- 
duction of  the  raw  material  into  the  furnace  to  the  production  of  the  pig  iron, 
has  heen  carefully  ascertained,  and  recorded  so  fully  that  any  one  in  the  trade 
can  readily  avail  themselves  of  the  knowledge  acquired ;  and  we  have  no  hes- 
itation in  saying  that  the  judicious  application  of  such  knowledge  will  do 
much  to  facilitate  the  introduction  of  arrangements  which  will  still  further 
economize  fuel,  and  at  the  same  time  permit  of  the  quality  of  the  resulting 
metal  being  maintained,  if  not  improved.  The  volume  is  one  which  no  prac- 
tical pig  iron  manufacturer  can  afford  to  be  without  if  he  be  desirous  of  en- 
tering upon  that  competition  which  nowadays  is  essential  to  progress,  and 
in  issuing  such  a  work  Mr.  Bell  has  entitled  himself  to  the  best  thanks  of 
every  member  of  the  trade." — London  Mining  Journal. 


King's  Notes  on  Steam. 

Nineteenth  Edition. 

8vo.     Cloth.     $2.00. 

LESSONS  AND  PEAGTICAL  NOTES  ON  STEAM,  the  Steam- 
Engine,  Propellers,  &c.,  &c.,  for  Young  Engineers,  Students,  and 
others.  By  the  late  W.  E.  Kixg,  U.  S.  N.  Eevised  by  Chief- 
Engineer  J.  W.  Ki2s'G,  U.  S.  Navy. 

"  This  is  one  of  the  best,  because  eminently  plain  and  practical  treatises  on 
the  Steam  Engine  ever  published.' — Pliiladelphia  Press. 

This  is  the  thirteenth  edition  of  a  valuable  work  of  the  late  W.  H.  King, 
TJ.  S.  N.  It  contains  lessons  and  practical  notes  on  Steam  and  the  Steam  En- 
gine, Propellers,  etc.  It  is  calculated  to  be  of  great  use  to  young  marine  en- 
gineers, students,  and  others.  The  text  is  illustrated  and  explained  by  nu- 
merous diagrams  and  representations  of  machinery.— J?(?S<(??1  Daily  Adv&r- 
User. 

Text-book  at  the  U.  S.  Naval  Academy,  Annapoli* 


28  SCIEWTIFIC  BOOKS  PUBLISHED  BY 

Bnrgh's  Modern  Marine  Engineering. 

One  tHck  4to  vol.     Cloth.     $25.00.     Half  morocco.     $30.00. 

MODEEN  MAEINB  ENGINEEEING,  applied  to  Paddle  and 
Screw  Propulsion.  Consisting  of  36  Colored  Plates,  259  Practical 
"Wood-cut  Illustrations,  and  403  pages  of  Descriptive  Matter,  the 
wKole  being  an  exposition  of  the  present  practice  of  tlie  follow- 
ing firms  :  Messrs.  J.  Penn  &  Sons ;  Messrs.  Maudslay,  Sons  & 
Eield ;  Messrs.  James  Watt  &  Co. ;  Messrs.  J.  &  Gr.  Eennio  ; 
Messrs.  E.  Napier  &  Sons  ^  Messrs.  J.  &  W.  Dudgeon  j  Messrs. 
Eavenhill  &  Hodgson ;  Messrs.  Humphreys  &  Tenant ;  Mr. 
J.  T.  Spencer,  and  Messrs.  Porrester  &  Co.  By  N.  P.  BimaH, 
Engineer. 

PnmciPAL  Contents. — G-eneral  Arrangements  of  Engines,  11  examples 
— General  Arrangement  of  Boilers,  14  examples  —  General  Arrangement  of 
Superheaters,  11  examples — Details  of  Oscillating  Paddle  Engines,  34  ex- 
amples— Condensers  for  Screw  Engines,  both  Injection  and  Surface,  20  ex- 
amples— Details  of  Screw  Engines,  20  examples — Cylinders  and  Details  of 
Screw  Engines,  21  examples — Slide  Valves  and  Details,  7  examples — Slide 
Valve,  Link  Motion,  7  examples — Expansion  Valves  and  Gear,  10  exam- 
ples— Details  in  General,  80  examples — Screw  Propeller  and  Eittings,  13  ex- 
amples-Engine and  Boiler  Fittings,  28  examples  — In  relatioa  to  the  Princi- 
ples of  the  Marine  Engine  and  Boiler,  83  examples. 

Notices  of  the  Press. 

"Every  conceivable  detail  of  the  Marine  Engine,  under  aE  its  various 
forms,  is  profusely,  and  we  must  add,  admirably  illustrated  by  a  multitude 
of  engravings,  selected  from  the  best  and  most  modern  practice  of  the  first 
Marine  Engineers  of  the  day.  The  chapter  on  Condensers  is  peculia^rly  valu- 
able. In  one  word,  there  is  no  other  work  in  existence  which  will  bear  a 
moment's  comparison  with  it  as  an  exponent  of  the  skill,  talent  and  practical 
experience  to  which  is  due  the  splendid  reputation  enjoyed  by  many  British 
Marine  Engineers."— ^w^meer. 

"  This  very  comprehensive  work,  which  was  issued  in  Monthly  parts,  has 
just  been  completed.  It  contains  large  and  full  drawings  and  copious  de- 
scriptions of  most  of  the  best  examples  of  Modern  Marine  Engines,  and  it  is 
a  complete  theoretical  and  practical  treatise  on  the  subject  of  Marine  Engi- 
neering."— American  Artisan. 

This  is  the  only  edition  of  the  above  work  with  the  beautifully  colored 
plates,  and  it  is  out  of  print  in  England. 


j9.   VAJV  jSrOSTBANI).  2S 

Bourne's  Treatise  on  the  Steam  En 

gine. 

Ninth  Edition. 

Illustrated.  4to.  Cloth.  $15.00. 
TEEATISE  ON  THE  STEAM  ENGINE  in  its  various  appHca. 
tions  to  Mines,  Mills,  Steam.  Navigation,  [Railways,  and  AgricuL 
ture,  with,  the  theoretical  investigations  respecting  the  MotivQ 
Power  of  Heat  and  the  proper  Proportions  of  Steam.  Engines. 
Elaborate  Tables  of  the  right  dimensions  of  every  part,  and 
Practical  Instructions  for  the  Manufacture  and  Management  of 
every  species  of  Engine  in  actual  use.  By  John"  Botjene,  being 
the  ninth  edition  of  "A  Treatise  on  the  Steam  Engine,'-'  by 
the  "Artisan  Club."  Illustrated  by  thirty-eight  plates  and  five 
hundred  and  forty-six  wood-cuts. 

As  Mr.  Bourne's  -work  has  the  great  merit  of  avoiding  unsound  and  imma- 
ture views,  it  may  safely  be  consulted  by  all  "who  are  really  desirous  of  ac- 
quiring trustworthy  information  on  the  subject  of  which  it  treats.  During 
the  twenty-two  years  which  have  elapsed  from  the  issue  of  the  first  edition, 
the  improvements  introduced  in  the  construction  of  the  steam  engine  have 
been  both  numerous  and  important,  and  of  these  Mr.  Eoume  has  taken  car© 
to  point  out  the  more  prominent,  and  to  furnish  the  reader  with  such  infor- 
m.ation  as  shall  enable  him  readily  to  judge  of  their  relative  value.  This  edi- 
tion has  been  thoroughly  modernized,  and  made  to  accord  with  the  opinions 
and  practice  of  the  more  successful  engineers  of  the  present  day.  All  that 
the  book  professea  to  give  is  given  with  ability  and  evident  care.  The  scien- 
tific principles  which  are  permanent  are  admirably  explained,  and  reference 
is  made  to  many  of  the  more  valuable  of  the  recently  introduced  engines.  To 
express  an  opinion  of  the  value  and  utility  of  such  a  work  as  T7ie  Artisan 
CluVs  Treatise  on  the  Steam  Engine,  which  has  passed  through  eight  editions 
already,  would  be  superfluous ;  but  it  may  be  safely  stated  that  the  work  is 
worthy  the  attentive  study  of  all  either  engaged  in  the  manufacture  of  steam 
engines  or  interested  in  economizing  the  use  of  steam. — Mining  Journal. 


Islierv/ood's  Engineering  Precedents. 

Two  Yols.  in  One.     8vo.     Cloth.     $2.o0. 

ENGINEEEING-  PEECEDENTS  EOE  STEAM  MACHINEEY. 

Arranged  in  the  most  practical  and  useful  manner  for  Engineers. 
By  B.  E.  IsHEEAvooi),  Civil  Engineer,  U.  S.  Navy.  With  illus- 
trations. 


80  SCIENTIFIC  BOOKS  PUBLISHED  BY 


Ward's  Steam  for  the  Million. 

New  and  Hevised  Edition, 

8vo.  Cloth.     $1.00. 

STEAM  FOE  TSE  MILLION.  A  Popular  Treatise  on  Steam 
and  its  Application  to  the  Useful  Arts,  especially  to  Naviga- 
tion. Bj  J.  H.  Waed,  Commander  U.  S.  Navy.  New  and  re- 
vised edition. 

A  most  excellent  work  for  the  young  engineer  and  general  reader.  Many- 
facts  relating  to  the  management  of  the  boiler  and  engine  are  set  forth  with  a 
simplicity  of  language  and  i)erfection  of  detail  that  bring  the  subject  home 
to  the  reader. — American  Engineer. 


Walker's  Screv/  Propulsion. 

8vo.     Cloth.     75  cents. 

NOTES  ON  SCEEW  PEOPULSION,  its  Eise  and  History.     By 
Capt.  "W.  H.  WALKEr.,  U.  S.  Navy.    . 

Commander  Walker's  book  contains  an  immense  amount  of  concise  practi- 
cal data,  and  every  item  of  information  recorded  fully  proves  that  the  various 
points  bearing  upon  it  have  been  well  considered  previously  to  expressing  an 
opinion. — London  Idining  Journal. 


Page's  Earth's  Oriist, 

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THE  EAETH'S  CEUST :     a    Handy    Outline    of  Geology.  .  By 
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ligible outline  the  leading  facts  of  the  science,  without  amplification  or  irk- 
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same  time,  forcible  in  style.  It  will  lead,  we  hope,  to  the  introduction  of 
Geology  into  many  schools  that  have  neither  time  nor  room  for  tho  study  of 
large  treatises." — TTiG  luuseum. 


D.  VAN  XOSTBAI^I}.  31 

Rogers'  Geology  of  Pennsylvania. 

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of  tlie  Coal  Fields  of  North.  America  and  Great  Britain.  By 
Heis^ry  Daiiwii7  Hoge-rs,  Late  State  Geologist  of  Pennsylvania. 
Splendidly  illustrated  with  Plates  and  Engravings  in  the  Text. 

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time  of  his  death,  are  now  offered  to  the  public,  at  a  price  which  is  even 
below  what  it  was  originally  sold  for  when  first  published. 


Morfit  on  Pure  Fertilizers. 

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A  PRACTICAL  TREATISE  ON  PURE  FERTILIZERS,  and 
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various  Yaluable  Products.     By  Campbell  Moefit,  M.D.,  F.C.S. 


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Coast.     By  S.  H.  Sweet.     With  maps. 


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D.    VAN  N08TRAND,  33 

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D.   VAN  NOSTRANB.  85 


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U.  S.  Navy. 

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sixteen  chapters  of  this  -work;  and,  to  obtain  a  complete  knowledge  of 
geodetic  surveying  requires  a  profound  study  of  the  whole  range  of  matbe- 
Inatical  and  physical  sciences ;  but  a  year  of  preparation  should  render  any 
intelligent  of&cer  competent  to  conduct  a  nautical  survey. 

Contents. — Chapter  I,  Formulae  and  Consents  Useful  in  Surveying 
II.  Distinctive  Character  of  Surveys.  III.  Hydrographic  Surveying  under 
Sail ;  or,  Running  Survey.  IV.  Hydrographic  Surveying  of  Boats ;  or,  Har- 
bor Survey.  V.  Tides — Definition  of  Tidal  Phenomena — Tidal  Observations. 
VI.  Measurement  of  Bases— Appropriate  and  Direct.  VII.  Measurement  of 
■the  Angles  of  Triangles — Azimuths — Astronomical  Bearings.  VHI.  Correo- 
tions  to  be  Applied  to  the  Observed  Angles.  IX.  Levelling — Difference  of 
Level.  X.  Computation  of  the  Sides  of  the  Triangulation — The  Three-point 
Problem.  XI.  Deterniination  of  the  G-eodetic  Latitudes,  Longitudes,  and 
Azimuths,  of  Points  of  a  Triangulation.  XXL  Summary  of  Subjects  treated 
of  in  preceding  Chapters — Examples  of  Computation  by  various  Formulas. 
XIII.  Projection  of  Charts  and  Plans.  XIV.  Astronomical  Determination  of 
Latitude  and  Longitude.  XV.  Magnetic  Observations.  XVI.  Deep  Sea 
Soundings.  XVII.  Tables  for  Ascertaining  Distances  at  Sea,  and  a  full 
Index. 

List  of  JPlates. 

PMte  I.  Diagram  Illustrative  of  the  Triangulation.  II.  Specimen  Page 
of  Field  Book.  III.  Hunning  Survey  of  r.  Coast.  IV.  Example  of  a  Running 
Survey  from  Belcher.  V.  Flying  Survey  of  an  Island.  VI.  Survey  of  a 
Shoal.  VII.  Boat  Survey  of  a  River.  VTIL  Three-Point  Problem.  IX. 
Triangulation. 

Coffin's  Navigation. 

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Pook  on  Shipbuilding. 

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METHOD  OF  COMPAEINQ  THE  LINES  AND  DEAUGHT- 
ING  VESSELS  PEOPELLED  BY  SAIL  OE  STEAM,  in- 
cluding a  Chapter  on  Laying  off  on  the  Mould-Loft  Floor.  By 
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IK  VAJSr  mjSTllAI^J).  37 

Van  Buren's  Formulas. 

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Illustrated. 

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Barnard's  Report,  Paris  Exposition, 

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since  the  Universal  Exhibition  of  1851,  and  we  doubt  if  anything  equal  to  it 
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D.   VAN  NOSTRAND,  39 

Stuart's  Civil  and  Military  Engineer- 
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I).   VAN  NOSTRAND.  41 

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THE  AET  OE  GEAINING.  How  Acquired  and  How  Produced, 
with  description  of  colors  and  their  application.  By  Chakles 
Pickert  and  Abraham  Metcalf.  Beautifully  illustrated  with  42 
tinted  plates  of  the  various  woods  used  in  interior  finishing. 
Tinted  paper. 

The  authors  present  here  the  result  of  long  experience  in  the  practice  of 
this  decorative  art,  and  feel  confident  that  they  hereby  offer  to  their  brother 
artisans  a  reliable  guide  to  improvement  in  the  practice  of  graining. 


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POETEAIT  GALLEEY  OE  THE  WAE,  CIVIL,  MILITAEY 
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Moore. 


One  Law  in  Nature. 

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Identity  of  Matter,  and  its  Multiple- Atom  Constitution,  applied 
to  the  Physical  Affections  or  Modes  of  Energy. 


42  SCIENTIFIC  B  0  OKS  !  UBLISIIED  B  Y 

Ernst's    Manual  of  Military  En- 
gineering. 

193  Wood  Cuts  and  G  Litliograplied  Plates.  12mo.  Clotli.  $5.00. 
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ING.  Prepared  for  the  use  of  tlie  Cadets  of  tlie  TJ.  S.  Military 
Academy,  and  for  Engineer  Troops.  By  Oapt.  0.  H.  Erxst, 
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neering, U.  S.  Military  Academy. 


Chnrcli's    Metallurgical    Journey. 

24  Illustrations.     8vo.     Cloth.     $2.00. 

NOTES      OF    A     METALLURGICAL     JOURNEY     IN' 
EUROPE.     By  JoHi^r  A.  Chuech,  Engineer  of  Mines. 


Blake's    Precious    Metals. 

8vo.  Cloth.  $2.00. 
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tion. By  William  P.  Blake,  Commissioner  from  the  State 
of  California. 


Clevenger's  Surveying. 

Illustrated  Pocket  Form.     Morocco  Gilt.     $2.50. 

A  TREATISE  ON  THE  METHOD  OF  GOVERNMENT 
SURVEYING-,  as  prescribed  by  the  United  States  Congress, 
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plete Mathematical,  Astronomical  and  Practical  Instructions, 
for  the  use  of  the  United  States  Surveyors  in  the  Field,  and 
Students  who  contemplate  engaging  in  the  business  of  Public 
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veyor. 

"  Tlie  reputation  of  the  author  as  a  surveyor  guarantees  an  exhaustive 
treatise  on  this  subject." — Dakota  Register. 

•'  Purveyors  have  long  needed  a  text-book  of  this  description. — TJio  Press. 


D.   VAN  NO  STRAND.  43 

Bow  on  Bracing. 

156  Illustrations  on  Stone.     8vo.     ClotL.     $1.50, 

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Bow,  0.  E. 


Howard's  Earthwork  Mensuration. 

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ly from  End  Areas.  Illustrated  by  Examples,  and  accom- 
panied by  Plain  Rules  for  practical  uses.  By  Cony/ay  R. 
HowAKD,  Civil  Engineer,  Richmond,  Va. 


"Major  Howard  has  given  in  this  book  a  simple,  yet  perfectly  accurate 
method  of  ascertaining  the  solid  contents  of  any  prismoid.  The  calculation 
from  end  areas  is  corrected  by  tables  well  arranged  and  few  in  number  ;  and  he 
has  all  the  accuracy  of  the  prismoidal  formulae  with  scarcely  more  trouble  than 
in  averaging  end  areas. 

H.  D.  WHITCOMB, 

Chief  Engineer  Chesapeake  and  Ohio  li.  li. 

E.  T.  D.  MYERS, 

Chief  Engineer  Richmond,  Fredericlcsburg^  and  Potomac  R.  RV 


Mowbray's  Tri-Nitro-Glycerine. 

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TRI-NITRO-GLYCERINE,  as  applied  in  the  Iloosac  Tunnel, 
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the  result  of  six  years'  observation  and  practice  during  the 
manufacture  of  five  hundred  thousand  pounds  of  this  explo- 
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U  S  CIENTIFIC  B  0  OKS  P  UBLISIIEB  B  Y 


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appendix.     Third  Edition.     Re-written. 


Wanklyn's   Milk   Analysis. 

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Toner's  Dictionary  of  Elevations. 

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DIC^TON^ARY  OF  ELEVATIOIS^S  AXD  CLIMATIC  REG- 
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Adams.    Sewers  and  Drains. 

{In  Press.) 

SEWERS  AND  DRAINS  FOR  POPULOUS  DISTRICTS. 
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D,  VAN  NO  STRAND,  45 


SILYEE  MINING  EEGIONS  OP  COLOEADO,  with  some 
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12mo.     Paper.     25  cents. 


COLOEADO :  SCHEDULE  OF  OEES  contributed  by  sundry 
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CHIMJ^EYS     FOR     rURNACES,     FIRE-PLAGES,    AND 
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s. 
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PRACTICAL    DESICOTNG     OF    RETAINING     WALLS 
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4- 

PROPORTIONS    OF    PINS    USED     IN    BRIDGES.      By 
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e. 
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AGE RESERVOIRS.    By  Aethxje  Jacob.    With  Illustra- 
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ING WALLS.    By  James  S.  Tate,  C.  E. 

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D.    VAN  N08TRAND.  47 


11. 
THEORY     OF    ARCHES.     By  Prof.   W.   Allan,    of  the 
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WITH  m  COAL-MINES.     By  the  late  J.  J.  Atkinsok, 
Government  Inspector  of  Mines  for  the  County  of  Durham, 
England. 

14. 
FRICTION  OF  AIR  IN  MINES.       By  J.    J.    Atki^s-son, 
autlior  of  ^^  A  Practical  Treatise  on  the  Gases  met  with  in 
Coal-Mines." 

15. 
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with  numerous  engravings  and  three  folded  plates. 

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GEBRAIC EQUATIONS.       By  Prof.   George  L.  Yose. 
With  illustrations. 

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field,  M.A.,  of  the  University  College,  London. 

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19. 
STRENGTH      OF      BEAMS      UNDER    TRANSYERSE 
LOADS.       By   Prof.  W.  Allaj^,    author  of    ^^  Theory  of 
Arches."     With  illustrations. 


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